Beelzeburb, The Story More Than a Decade in the Making

[Beelzeburb]

Gee, now that I've gathered most everything for my GenIV install, VintageAir comes out with a bolt on kit. Oh well, I've got the stuff so yesterday I decided to start on the install.

I'm doing this now because I've got my 240Z almost completely reassembled after I painted it:


Plus, my 510 is now a running and drivable vehicle but I'm waiting on a sheetmetal shrinker/stretcher so I can keep making my own patch panels for it. By default that left the Suburban to play with.

Yesterday afternoon I unpacked the GenIV evaporator unit and started reading over the instructions. The front and rear mounting brackets were the first to go on. Well, I soon learned that the heater fittings needed to be fitted before that, so off came the rear bracket, and then back on again.



I gathered up some spare 2x4s from last summer's kitchen remodel, stacked them up and wedged the unit roughly into place. Now I could get an idea of where everything fit in relation to the unit, and it made it much easier to visualize where my mounting brackets would sit.



I had been concerned that the upper mount might interfere with the power distribution block and the fuel pump relay that I'd already mounted behind the dash, but they cleared just fine. It was also pretty tricky taking a decent picture with the extreme contrast of deep black POR-15 and the bright white dash. My DSLR would have done better, but my little point & shoot Kodak is more 'expendable'.

I took some measurements and re-read the CustomClassicTrucks article for some guidance. Late last night I bent up this bracket:



My brother in law had come across a hood from a Dodge D100 sitting abandoned in a field one day while out jogging and it has been donating sheetmetal to my projects, including this bracket. It's 6.5" wide where it mounts to the VA evaporator unit, it sits off the firewall 2.25" and the legs are 1" wide each for a total of 13" wide x 10.5" tall. I welded four pieces of threaded rod, one on each corner so that the GenIV unit's rear bracket slips right over them.

This morning I trial fit the new bracket in place, but saw that one corner would have to be trimmed.



The unit had to be that close to the center of the vehicle. Otherwise there would be absolutely no space to route the hoses to the firewall bulkhead.



That last picture helps show the space constraints. I was holding the bulkhead as close to the outside edge as I reasonable could. I'd only tacked my bracket in place and hung the GenIV unit on it to make sure things were lining up properly. Everything looked okay, so off came the evaporator unit and the bracket was welded on for good. Then the evaporator went back on again so that I could take final measurements for the upper mounting bracket. Unfortunately I didn't take any pictures of the fab process for the upper mount. It was just a simple "S" shaped piece with four angle braces. The top of the GenIV unit sat 4.5" from the firewall, so I made it 6.5" long and bent the last 1" of each side for the mounting part then welded it to the firewall.

The last big step for the day was to cut a hole i the firewall for the vertical billet bulkhead. VintageAir supply good instructions and a handy template for this job. I tried center punching and drilling 1-1/4" holes in the ends like the instructions call for, but my 1.25" hole saw was hopelessly dull.



Instead I cut the long straight sections with my angle grinder and traced around the corners by hand with the Dremel. Not the cleanest solution, but it worked well enough.



Now the portion inside the cabin is ready to be recoated with POR-15 and then the GenIV evaporator unit can be bolted down for good. After that I will make the engine bay side of the firewall completely smooth with no traces of the old system.

[Kevin McPherson]

I just started reading about your suburban,from front to last entry. NICE. You sound like alot of us on here,lol. Very nice with the 240 BTW!! I hope to see you finish finish it.I am just starting a "refresher" thread on a 67 4x4.

[VA72C10]

Nice work on the A/C and the Z looks good too!!!

[vectorit]

Always look forward to your updates!

Very curious about how the AC goes in, and how it performs in a Suburban.

[Beelzeburb]

You know, I'm interested to see how it works too vectorit. I'm not sure how well it'll compare to an installation with a full Vintage Air kit though because I'm reusing my old R4 compressor and 1970 era condenser. The condenser is huge at 28.5” x 12.5” x 1.25” thick, but it's a tube and fin style.

Glad you guys like the Z. It is my first full vehicle paint job and I'm fairly pleased with how it came out too. Gave me some experience for future projects (and an appreciation for how much work goes into a quality job).

I forgot to mention that I finally got a little color on my Suburban. I had been using the original hood from it as a test panel when I painted the Z, so that one piece is mostly blue now (with a grouping of runs on one side and plenty of thin spots too). It took a little getting used to since I hadn't seen any sort of color on the Suburban for a long, long time.



Well, a week or two ago I bought 8' of 5/8” heater hose as recommended in the Vintage Air instructions. The first two pieces I needed were only 3” long each. They attached the evaporator unit to the firewall bulkhead.



Close, but not too close.



The other fittings were a little trickier. I'm keeping the stock style coolant flow routing as found on the '88 truck my engine came from. Intake manifold > heater core in > heater core out > radiator. Luckily, my Suburban's old four core radiator has a handy built in port on the outlet side tank for the heater return hose, just below the transmission cooler inlet.



The fitting that was at the rear of my Edelbrock intake, on the other hand, was sized for 3/4” heater hose. Meanwhile, the Vintage Air unit utilizes 5/8” size hose. Of course, none of the stores in town (including dedicated plumbing outlets) had a 3/8” pipe taper to 5/8” hose barb fitting (kind of an oddball size I guess) so I ordered one online. The company accidentally sent me two, so perhaps 10 years from now I'll find a use for the second one. Here's a size comparison between the 5/8” fitting and the 3/4” one.



While waiting for the new brass heater fitting I made a patch for the hole that had been the prior dwelling place of the fan blower motor.



With the firewall completely smoothed I slathered it with two coats of POR-15, but my can was almost empty and the remnants that had settled to the bottom of the paint receptacle made it come out all bumpy (well, that and the fact that I was painting during a snowstorm). I'll sand it smooth yet again and put on a fresh coat when the new quart that I have on order arrives.



I still need to plumb the heater valve and run the wiring for the evaporator unit, but it's getting close. Yet another “to do” involves cutting holes for the side dash vents. I found a template from Vintage Air for the center vent and chopped that one out real easy. The repro center vent that had been sitting in my collection of stuff for a few months didn't come with mounting hardware. I searched the boards here and found that 1/4” threaded rod worked as a substitute for the original stuff. So, after spending $1.97 at the hardware store for a few feet of 1/4” - 20 rod I cut it to length. A quick run through with a tap and some red Locktite should hold them in the back of the vent fairly well I think.





Some small stuff I've taken care of recently:

The battery cables are hooked up now. I bought a longer positive which was snaked down along the frame (firmly attached so it can't swing into the headers) and to the starter. The smaller positive lead follows it then snakes back up behind the engine and into the cab where it attaches to the power distribution block. I recycled the old positive cable that had been too short and grounded it to the block.

The 454 is now primed with oil. Finally unpacked my Summit Racing tool and chucked it up in the drill. I was relieved to find that there is just barely enough room to pull the dizzy out and clear that firewall, but the cap and rotor have to be removed first. I ran the drill enough to drain the 80 gallon tank on my compressor three times and called it good.




No matter how much I looked, neither my '89 Unit Repair Manual or the '93 Service Manual show any procedures for properly installing and / or aligning the distributor. Perhaps they're included in the Fuel & Emissions supplement that I don't have? With the engine at #1 TDC I aligned the rotor with the #1 post on the cap as best I could. Hopefully it'll be close enough to get it fired up and then set the timing properly at 4°.

In preparation for routing the A/C lines (hose kit is on the way now), I hooked up the Vintage Air adapter block to the R4 compressor. It's looking like the bracket just behind it might get modified to allow better clearance. Can't tell for certain until the fittings arrive.



I started sorting through all the items which positively will not be used again. Items like the old transmission linkage, A/C hardlines, under dash temperature gauge, etc... While digging through boxes I found a a bag with instructions and leftover hardware from the K&N air cleaner. It tuned out that I'd left a vent fitting off which was meant to be bolted to the bottom of the chrome housing. This only added another mystery item to my list of things left to hook up. There weren't any unused fittings that size on either the intake manifold or TBI, so it remained a mystery for a few days. Then I remembered another mysterious hose of similar size. There are three lines connected to the fuel pump. I knew that two of them were obviously fuel feed and return, but the third had been an unknown for quite a while now because it was a bit larger than the other two (another item that's covered in the fuel & emissions supplement?). Then it occurred to me that if it were a vent line, then the air cleaner would be a very logical spot for it to attach. Two birds with one stone there.

[Beelzeburb]

Received the A/C hose kit the other day. I started mocking up hose routing. I quite like the little hose cascade effect on the inner fender.



A pleasant surprise came when I discovered that the Vintage Air fittings thread right on to the original style hard lines which lead to / from the condenser / evaporator.



A not so pleasant surprise involved encountering some difficulties with the fittings meant for the compressor. The beadlock crimp A/C line kit comes with two 135° fittings (-8 and -10 sized respectively, but really meant for the Sanden compressor's orientation) which have built in service ports and thread directly onto the compressor. I tried as many of the limited orientations as seemed plausible, but none routed the hoses conveniently while allowing reasonable access to the service ports.



Oh, and I did have to remove that bracket I had mentioned in my last post in order to get the -10 fitting in place. While it was off I performed a couple of modifications. The top of the bracket came off, was turned 180° and a 1/4” tall piece of plate welded in between the two pieces to raise it up a bit. This way the EGR pressure valve solenoid is still secured properly, the PCV line is unimpeded and it clears plenty of space for the compressor fittings (all while still fitting underneath the air cleaner).



I decided to ditch the 135° fittings altogether. There simply wasn't a good way to make them work, so I've now got some 90° ones on the way. When they arrive then I can mark hose orientation for the last remaining connections and then get them all beadlock crimped. In the meantime I've got plenty more tasks to resolve. The first one I tackled was to mount the A/C controls in the dash. The '67-'72 GenIV kit comes with adapters to retain the factory cable controls, but I've already got the 3 knobber electric jobber.

First, cut a plate to match:



Weld:



Make a new hole according to the template included with the instructions:



Test fit control panel:



I didn't get that upper edge quite as closely aligned as it could have been before welding. After a very thin skim coat of filler, a smidgen of primer and some paint it should be good to go though. After this I tried to fit the new evaporator/drier with trinary safety switch from Vintage Air. I hadn't anticipated a fitting incompatibility here, but nevertheless there it was.



You win some you lose some. I weighed all of the options here. I could have tried to return the drier assembly. If I had done that then I'd have need a factory style drier instead, and I'd still have had to buy a safety switch then plumb it inline somewhere in the system. After some waffling I decided to keep the new drier and try to find two straight -6 female O-ring pilot to -6 female O-ring pilot fittings instead (like trying to find hen's teeth and probably just as expensive if they even exist). This way the drier will sit in the stock location, use the stock hard lines and I won't need to change anything else or deal with trying to return a part that I had already opened and relieved the pressure from.

[FRENCHBLUE72]

Very nice good to see ya still pluggin away at your burb..

[SOON2BLAZE]

Nice progress!

[mosesburb]

Originally Posted by Beelzeburb

While digging through boxes I found a a bag with instructions and leftover hardware from the K&N air cleaner. It tuned out that I'd left a vent fitting off which was meant to be bolted to the bottom of the chrome housing. This only added another mystery item to my list of things left to hook up. There weren't any unused fittings that size on either the intake manifold or TBI, so it remained a mystery for a few days. Then I remembered another mysterious hose of similar size. There are three lines connected to the fuel pump. I knew that two of them were obviously fuel feed and return, but the third had been an unknown for quite a while now because it was a bit larger than the other two (another item that's covered in the fuel & emissions supplement?). Then it occurred to me that if it were a vent line, then the air cleaner would be a very logical spot for it to attach. Two birds with one stone there.

This sounds wrong. The fitting on the bottom of the air cleaner base should go to a valve cover (the one that does not have the PCV valve in it). TBI motors used an air cleaner extension between the air cleaner housing and the TBI and on this extension was a nipple. A hose connected that nipple to the valve cover originally so you may be able to use that instead of the fitting on the air cleaner base, but either way what you described doing with the fitting and a fuel pump sounds wrong to me, but maybe I am just misunderstanding what you meant.

[Beelzeburb]

Looks like I was describing it wrong mosesburb. I looked at the line from the tank on Wednesday and it is a smaller diameter than I remembered. A 1/4" hose fits snugly on it. The fitting on the air cleaner is quite a bit larger. If the fitting on the underside of the air cleaner turns out to be unnecessary (since I have a filtered breather to the open air on the driver side valve cover) it'd be easy to put a rubber plug in its place instead.



The earlier guess about line routing was based on a couple of my older carbureted cars. On one of them it has a separate vapor recovery tank which sits above the fuel tank, and a line runs from the vapor recovery tank up to the engine bay. From there it connects to a valved tee where one end leads to the air cleaner and the other leads to the crankcase.

The '88 engine I've got originally had a charcoal canister and A.I.R. system, but I've removed them. I'm trying to imagine what the original engineers intended and replumb accordingly. Unfortunately I don't have a manual which describes the emissions system in any detail. I'll probably buy the fuel & emissions manual from an Ebay seller just to make sure I hook everything up right.

I have left the MAP sensor, PCV valve and EGR pressure valve solenoid hooked up to the proper ports on the TBI unit. That left two extra unused (small) ports which I blocked off. I assumed that the unused ones had lead to the air pump and charcoal canister. The instructions on the Edelbrock intake manifold say that the MAP sensor port can be teed from as well if the transmission has a vacuum modulator, but I don't believe I need that.

Still gotta figure out where that small fuel tank vent line was meant to go. I do have the old fuel pump from the '88 truck handy for reference.



From left to right we've got 1. vent to fuel filler neck (large diameter) 2. fuel feed 3. fuel return and 4. mystery vent line (small diameter).

Here are the three that run along the frame, near the transmission. The vent line is the one with the rubber hose on it.



I guess it depends on what the manual says. Without it I'm assuming that either it'll get vented to the open air with a check valve, or, more likely it'll lead back to the air intake path somehow so that the fuel vapors are burned instead.

Oh, also a very special thanks to mosesburb for graciously digging through his old reciepts for me. With his help I now have longer rear parking brake lines for my Suburban (ACDelco DuraStop 18P266).

[mosesburb]

The small diameter line on your sending unit goes to the charcoal canister. I recommend reinstalling one if you took it out. Every vehicle I have taken one out of I have put one back in because of the ever-present fuel odor that can not be gotten rid of. A buddy of mine did the same thing. Couldn't figure out why his 72 K5 always reeked of fuel. I didn't realize he took it out, so that one took a while to solve. If you decide to add one back in, I have a TBI canister and 72 bracket here that came off of mine when it had the big block in it. It has about one mile on it.

If possible, on your MAP sensor, do not tee it. It *should* work, but I have dealt with strange MAP issues on one that was tee'd. If there is no other way, then so be it, but if you can use one port dedicated, it would be preferred.

[Beelzeburb]

Thanks mosesburb, some good advice there.

Here's a page from my Automobile Guide printed in 1972 which describes the basics of the kind of system I was envisioning (perhaps a bit primitive by today's standards).



I'd think that it would work, but that it would probably be a good idea to plumb a valve inline that only opened above a certain pressure. My Fuel & Emissions supplement is on the way now, so I'll have a better idea of the overall scheme of things soon.

In the meantime I mounted the ECM securely today with a couple of small brackets that are mostly out of sight. It now hangs snugly above the new fuse panel.

[mosesburb]

Originally Posted by Beelzeburb

Thanks mosesburb, some good advice there.

Here's a page from my Automobile Guide printed in 1972 which describes the basics of the kind of system I was envisioning (perhaps a bit primitive by today's standards).



I'd think that it would work, but that it would probably be a good idea to plumb a valve inline that only opened above a certain pressure. My Fuel & Emissions supplement is on the way now, so I'll have a better idea of the overall scheme of things soon.

That should work fine, but with this sending unit the 1/4" line is all you need. If you look at the underside of the sending unit where the 1/4" line enters it, and see that "thing" on the end of the 1/4" line?? That is the positive pressure valve that you want to put in. GM beat you to it. You do need a charcoal can on the end of that line though....

[Beelzeburb]

Beat me to it.
I was just researching the function of the charcoal canisters and it seems they're a little more advanced version of that "vapor-liquid separator" in the diagram I posted. Helps filter fuel vapors so they can't enrichen the intake mixture.
I had been wondering about the "thing" too. I'd surmised that it was a valve of sorts, but the exact function wasn't yet certain without the manual. Thanks again for helping clear things up.

[Beelzeburb]

Almost done with all of the plumbing on the Vintage Air install now. I'm only waiting on one hardline to bend up as a replacement for the drier > evaporator line. I tried ordering couplers to overcome the drier fitting conundrum, but ORB (which I ordered erroneously) is completely different than O-Ring Pilot (which I really needed, but they don't exist in this style), so I came up with another solution for that. I'll take a picture of it when it's in place.

At the beginning of the week I cut all of the flexible hoses to length and marked their orientations together with the fittings.



Then I had to find someone close by who could crimp them correctly. I visited four different businesses that were only equipped to crimp hydraulic hose, but at the last one they led me to a local diesel repair shop. Probably the only place in this town of population 29,000 with an ATCO 3710 beadlock crimper. $21.21 later and I was on my merry way, glad to have found someone close to home to do it for me.

Here is the passenger side of the engine bay again, this time with the lines all in place and tightened down with properly oiled o-rings.



I plan to eventually secure all four of those hoses to the inner fender with a bracket of some sort. I had also taken the liberty of block sanding the firewall flat again with some 220 grit and then brushing on another layer of POR-15. It came out much smoother than before (it had looked horrible, I hid it by angling the camera and keeping the area in shadow), but still with a little bumpiness which I attribute to the strong winds that day.

Here's a shot of the 90° fittings on the compressor which should make it much easier to get at the service ports compared to those 135° fittings that came with the hose kit. I'll probably have to turn that plastic wire holder on the left 180° around though. That'd make it easier to connect to the lower service port.



Here's another small project I've been working on, getting the spark plug wire holders I ordered to play nice with my motor. I've heard of the term “bolt on” but in my experience it seems more like a theory than a fact.



They are R&M Specialties 1102K billet wire looms made specifically for the big block Chevy. Unfortunately, I couldn't just bolt them down because they didn't clear the firewall on either side, so I had to make my own adapter plates to move them forward enough to clear. I didn't want to modify the brackets themselves because they're aluminum (I don't have the equipment to weld aluminum) and they're anodized black (ditto on lack of equipment here too). So instead I broke out the chop saw, drill press and welder. All they need now are some nuts and lockwashers then a little black paint and they'll be hardly noticeable.

Oh, I did get a service manual supplement in the mail this week, but they sent me the wrong one. The correct fuel & emissions supplement is now on it's way.

[Beelzeburb]

Hey, wait a second. Me throwing something away? Impossible!



It just took some more digging through the herd of parts boxes to find a vapor canister. It’s fairly simple and straightforward with one input from the tank vent line and one purge to the throttle body. There is a larger outlet that’s marked “air cleaner” but it’s blocked off with a snug little bespoke cap that looks factory installed. I’m thinking it might get mounted to the front inner fender somewhere, out of sight as much as possible but still keeping it above the level of the gas tank so that it can operate properly. I finally obtained the correct Light Duty Truck Fuel & Emissions Service Manual Supplement today. After simply thumbing through it, many questions have been answered so far. For instance, I had been wondering if my engine originally had a knock sensor or not, but according to the manual it didn’t. That’s one less thing to worry about finding and wiring in.

Here’s another recently completed part, the trans hump.



Obsessive compulsive much? Yes, I bought ten new stainless steel bolts and washers to hold it down even though the original pieces were still in serviceable condition. I’m going to have a plethora of 1/2” bolts left over when I’m done (would you say I have a plethora of piñatas?). It was coated top and bottom with two coats of POR-15.

As promised, I’ve got some photos of my solution for the fitting incompatibility at the receiver/drier. Yesterday morning UPS brought the 30” -6 line I ordered from Vintage Air. Instead of the original style line which had two male fittings, this one had one male and one female. I broke out the tubing bender and formed it to approximate the original item.



It worked exactly as intended. I coulnd’t find a female-female line for the other side, so instead I used some leftover flexible hose and fittings to make it work.



No more uncongenial (yes, I do own a few thesauri) fittings!



It’s a complete, sealed system now. There are very few items left on the A/C install to-do list and I’m quickly whittling it down further. Last night I secured the heater inlet hose to the block with a clamp so that it can’t melt on the header. A 3’ piece of heat resistant hose sleeve is on the way to cover it as well. Today I plumbed the heater valve inline at the back of the engine. I ran the defroster flex hoses to some new vents that I bought from Brothers recently. While trying to take a picture of all the vents together with their adapters some dachshund puppy decided to play Gojira with the parts I’d stood up on the floor and then steal the focus in my photo.



I also fabbed the remaining spark-plug-wire-holder-bracket-adapter-majig yesterday.



They both gained two coats of primer and some flat black paint that I found in the local gaggle of spray cans.



Very inconspicuous now. Speaking of subtle and unostentatious items, there’s a new hole in the license plate bracket for my hidden hitch.



Stealthy indeed. The only part I can’t figure out is how to put the retaining clip in the receiver pin because both the license plate bracket and hitch get in the way. I’ve got all the bolts on the plate bracket tightened down now with the flip up frame and license plate slapped on. My tags seem to have mysteriously expired nine years ago. Oh, one final thing to mention. Today I won an E-bay auction for a NOS pair of ‘68-’72 Utah license plates that just might find their way onto the Suburban when it comes time to register this thing once more.

[VA72C10]

Nice progress. And a very sesquipedalian post

[FRENCHBLUE72]

Very well typed out post and very informative...

[Beelzeburb]

Well, just a quick update on the last fiddly bits for the A/C system. I purchased some shiny aluminum brackets and bolted them down to the inner fender. They'll help keep the hoses from chafing.



Tired of wondering what to do with the old A/C hoses for the rear air unit, I finally removed them completely.



Ever curious about the length of these puppies? Mine measured out to 26' when straightened, plus an unknown length that had been cut when the unit was removed. Don't worry though, I kept them in case of an eventual need.

Wait, what's this here?



That's right, I put the rearview mirrors back on!

Oh, you were wondering about the fact that the lights are on? Yeah, I guess I kinda wired the whole vehicle during the last two weeks as well. If you don't want to read about all of my adventures in Electron Land®, then feel free to skip to the last paragraph. I didn't take many pictures because unless someone explained what you're looking at and could also contrast it with a wiring diagram, the wires all just look like colorful jumbled spaghetti.

You know, like this:


This was it, the big roadblock; that one job I'd been dreading for years.
There were five major wiring groups to tackle:
1. American Autowire Power Plus 18 fusebox and harness (lights, fuses, power to most accessories)
2. Vintage Air A/C harness
3. 1988 ECM harness
4. Compushift transmission controller harness
5. Instrumentation

They were dispatched in that order. I tried to start with the easy stuff. First came the final mounting of the fusebox and unfurling the light harness leads. Headlights, horn, turn signals, taillights, electric fan, fuel pump, fuel tank sending unit and reverse lights started the ball rolling. For the most part the Power Plus 18 kit was very easy to work with (they don't make the 18 any more, but they do sell a 20 circuit Power Plus kit). The instructions were very good and they included a full color wiring diagram for the entire system. Even the individual wires were screen printed with their intended use every few inches. One thing that caught me off guard right away was the fact that there was no provision for a reverse light lead built into the system, anywhere. Instead, I repurposed the wire marked “Third Brake Light” for this task. I'd have thought that backup lights would be a standard inclusion. The rear light wires were routed in the factory style, up through the a-pillar, along the roof and then back down through the d-pillar. The rear harness was just barely long enough to reach the driver side light. I simply tapped into the original passover for the passenger side lights. All but two of the original firewall holes are now filled (except for the three directly aft of the engine, where they're mostly hidden), so the old choke and speedometer cable holes are now a pass-through for the A/C, front lighting, horn and electric fan wires.

The AAW kit is GM color coded and designed for custom installations. Most of the wires were the same colors as those found on my old '70 harness, but the AAW kit didn't include many of the plastic connectors specific to the truck. Keep in mind that these sort of things are included in their Classic Update and Factory Fit kits. As an example, I had to remove the plastic connector for the headlight switch from the 1970 harness (depress tabs on crimped connectors, pull out wires) and plug the new wires into it.




Other plastic connectors that I had to reuse were for the ignition switch, brake switch and courtesy lights. For whatever reason, AAW included the right dimmer switch connector in their kit though. I was lucky enough to already have a tool that could properly crimp the non-insulated connectors included in the kit. To buy the two tools recommended by AAW would have cost approx. $200, but I got away with using a $30 tool that did the job just as well. Those wires are not coming loose, they are very solidly crimped. Just as an example, I had the CD player stolen out of my DD once when I lived in the Phoenix area. I had crimped the CD player's pigtail harness to the original wires from the old head unit with butt connectors and this crimping tool. When the thief yanked out the deck, none of my crimps failed. On the contrary, two wires snapped and most of the pins pulled out of the back of the head unit instead. I love this crimping tool.

Other things I was disappointed that AAW didn't include in their wiring kit: brake warning switch / light wiring, alternator / charge warning wiring, coolant light wiring (the one that's tied into the ignition switch), plus wires to the courtesy lights and cigarette lighter. I simply reused most of those, or cut new pieces of color correct wire from the leftovers of the '88 harness. The windshield wiper motor and switch wiring had to be excised from the old harness and reworked as well, though AAW did provide a fused circuit and power wire lead for the wiper motor.

With those basics completed and functioning (I managed to break my first headlight switch and had to order another one or else I would have come forth with a picture like the third one in this post much sooner) it was time to start routing wires for the Vintage Air Gen IV unit. It came with a dedicated wiring harness and 30 amp circuit breaker. Even though the AAW kit has a fused circuit assigned solely to A/C, the VA instructions told me to place it's power and ground wires as close to the battery as possible. The large, red power wire from the circuit breaker was routed to the positive post on the starter, while I managed to merge the two ground wires in with the main engine harness and firmly attach them together with the ECM grounds on the thermostat housing. Next, there was an easy feed and return loop which fit on the heater control valve. After that I used 30' of blue wire to reach from the interior, passenger side where the Gen IV unit was, across the interior to the driver side, out through the old speedometer cable hole into the engine bay, over the top of the inner fender to the core support, into the plastic wire retainer and across the core support to the passenger side, through a grommet in the core support and finally spliced into the A/C safety switch. Then another blue wire left the opposite end of the safety switch and retraced all of that to splice into the A/C compressor clutch lead in the main engine harness. Hence the need for 30' of wire. The last A/C wire was a small one which spliced smack dab into the ignition switch and signaled the unit to power up when the key was in the 'On' or 'ACC' position.

Let's see, what do I remember of the ECM harness? Well, it already included leads to the coil and starter, so I didn't need those wires from the AAW kit. All I had to do was plug them into the right connectors on the AAW harness and call it done. Though I did get to use the AAW tach wire from the other post on the coil to the ECM and tachometer. There were a few other mysteries though. Eventually, and after finding all of my wiring diagrams I'd printed out years ago, it all started to make sense. Even though I stumbled upon the connector for the Hot Fuel Module, the unit itself was missing. There was another plastic three wire connector adjacent to the Hot Fuel Module which the service manual says is an A/C connector, but the wiring colors don't correlate to anything on the diagrams I've got so it remains a brainteaser in the meantime. The other loose wires and connections which had yet to be made were: fuel pump feed (the fuel pump relay already gets power straight from the battery and has an inline fuse) and ground, auxiliary cooling fan lead from relay, oil pressure sensor lead to instruments, water temperature sensor lead to instruments, fuel injector power to fused circuit, ECM power to fused circuit, heated O2 sensor power (an addition of mine) to fused circuit, a few loose grounds, an ECM to NSS wire and a fused connection to the cranking circuit on the ECM.

After all of that, the Compushift transmission controller was a breeze.

Two plugs simply snap in place on the transmission and the TOSS, which on my rig is at the back of the transfer case. One difficult bit was figuring out how to get those things through the existing holes in my firewall without having to drill any new ones. I wound up taking apart the D-sub connector at the transmission controller side then just barely being able to slide it through a 1” firewall hole (already half filled with wiring) and reassemble it again on the other side. The other connections were switched 12V power, a ground, two wires which spliced into the TPS signal, one which spliced into the RPM signal from the coil and a wire which reproduced the TOSS signal and would feed the speedometer.

Last but not least were the Autometer gauges. They were very simple and straightforward. Even the AAW instructions included a diagram to help hook them up correctly. Many crimped blade connectors later, and it was all in place. I did have to modify the twist-lock turn signal bulb holders though. Since I no longer have a printed circuit board, they needed both power and ground wires which I fed through holes drilled in the back of each one. Oh, the oil pressure sending unit that had been on my engine was the wrong ohm range (needle went straight to 100+ p.s.i. with key on) for the new gauge, so I had to switch it out for the one that came in the Autometer package.

Now I am at the troubleshooting phase. The TPS isn't reading correctly yet (at a constant no matter where the throttle is), the gauges don't light up with the headlights on, I think I've got the fuel pump feed and fuel gauge wires reversed (gauge jumps up to 3/4 tank with key on and fuel pump doesn't engage), the transmission temperature is reading -5° in Fahrenheit, I've yet to mount the auxiliary cooling fan and I still need to remove the steering column to cut a hole in it for the neutral safety switch. Despite all of that, I jammed the big purple NSS wires together and the starter turned the motor over for the first time in 6 years. I will say one thing to end this though, an uncorked 454 dumping straight out through open headers is LOUD! I couldn't resist one quick spritz of starting fluid.

[FRENCHBLUE72]

Congrats on the fire-up.. Very nice easy to read and very informative post..

[y5mgisi]

Yet another thread that i have missed up until this point! What a *****en build! Great job on everything you have done! I love builds like this where people go the extra mile for the sake of quality fit and finish. Inspirational!

[Mt Man Chad]

This is one great build and story!

[Beelzeburb]

Originally Posted by FRENCHBLUE72

Congrats on the fire-up.. Very nice easy to read and very informative post..

Thank you. I couldn't stop smiling for quite a while after it ran for 1.2 seconds. I'd just been reading through your project thread and it looks like you've been through the wiring phase yourself recently. Waiting to see when the other projects are out of the way and work resumes on the truck.

Originally Posted by y5mgisi

Yet another thread that i have missed up until this point! What a *****en build! Great job on everything you have done! I love builds like this where people go the extra mile for the sake of quality fit and finish. Inspirational!

Originally Posted by Mt Man Chad

This is one great build and story!

Hey, thanks guys. I'm trying my darndest to do this once so that none of it has to be redone later, just enjoyed.

As of this morning, there sits somewhere in a Southern Utah junkyard's 'crush pile' a Chevy Van without a fuel filler flap or neck. I wonder where those are going to go? Hmmmmm.....

[Beelzeburb]

Test fit is going well so far. Before final welding I still have to section the filler hose and vent lines. The van's tank sat a little lower in the vehicle than the one in my Suburban and didn't have the same curves. I will gain the correct unleaded restrictors though.





Think I found the reason my TPS wasn't reading correctly.



Thank goodness for DIYAutoTune.com and their most excellent selection of affordable Weather Pack connectors, including the GM inline TPS specific one I needed. Now it reads like it should.

[jbclassix]

what are your plans for your t-case shifter?