Voltage issue - Gauge Cluster and wiring Questions

[FirstOwner69]

Also, after you changed the fuses, did you see any ammeter needle deflection in either direction? Did the fuses blow again?

[greywurm]

Any idea if part # 36-3530 is the portion of harness that will replace the alternator wires?
From LMC

[greywurm]

Originally Posted by FirstOwner69

Also, after you changed the fuses, did you see any ammeter needle deflection in either direction? Did the fuses blow again?

No fuses have blown. I have yet to notice the needle in the ammeter move. Its always a little bit to the right of the middle of the gauge. Running, off, gauge removed... always seems to stay put.

I'm considering ordering a replacement ammeter gauge from LMC as well... but I am not sure if it will actually fix anything. I haven't confirmed if the wiring for it is correct. But I also don't know where in the high res diagram to look.

[FirstOwner69]

Originally Posted by greywurm

Any idea if part # 36-3530 is the portion of harness that will replace the alternator wires?
From LMC

The description sounds right, BUT there is no differentiation noted for idiot light vs. gauge clusters.

EDIT: Here's a link to one at Classic Industries that specifies it's for gauges. I'm not sure if that would be what you need though. http://www.classicindustries.com/tru...s/ct22220.html
There is a 20% off code in the promo code thread if you go that route. Post 508. http://67-72chevytrucks.com/vboard/s....php?p=6716077

[FirstOwner69]

Dumb question...do you have the fusible link wire from the positive battery post cable to the junction box on the right fender?

Does the ammeter deflect to the left of center when you turn the headlights on?

[greywurm]

Originally Posted by FirstOwner69

Dumb question...do you have the fusible link wire from the positive battery post cable to the junction box on the right fender?

I believe that is the wire I was asking about early on that wasn't connected to anything and sparked on me once when i touched it to the junction. Let me go out to the truck and snap a picture of what I think you are talking about...

EDIT: the pic

[FirstOwner69]

Originally Posted by greywurm

I believe that is the wire I was asking about early on that wasn't connected to anything and sparked on me once when i touched it to the junction. Let me go out to the truck and snap a picture of what I think you are talking about...

Note that I added information about Classic Industries to post 29 and a second question to post 30.

[FirstOwner69]

Originally Posted by greywurm

I believe that is the wire I was asking about early on that wasn't connected to anything and sparked on me once when i touched it to the junction. Let me go out to the truck and snap a picture of what I think you are talking about...

EDIT: the pic

The one you are holding is the ammeter shunt wire. Is the battery post in the pic the negative post? Does the red wire going into the junction block from the back come from the positive cable clamp? If so, that would normally be a fusible link.

[greywurm]

Originally Posted by FirstOwner69

Does the ammeter deflect to the left of center when you turn the headlights on?

No. It never moves.

Since it's dark out, I got to see my headlights at night since the improvements I made on wire joins... The head lights are brighter.

But I also noticed that my blinkers are odd... they work differently with the headlights on than the headlights off... maybe my issue is here?

hazard - tail, front side marker, and parking lamps blink together, both sides. timing is on then off immidiately, staying off for about one second. turn the headlights on, the parking lamps stay on, never off, and the blink pattern is longer. the front side markers stay on for about one second then off, then back on. The tail lights are on when the front side markers are off. I can also hear the clicks at a different rate.

left turn signal - headlights off, the pattern is longer than the hazards. stays on for about half a second, goes off then immidiately back on. if it stays on for a while, it eventually just stays on.

right turn signal - headlights off, it is slow... i think the battery is pretty drained now. All in all, when the headlights are on, the front parking lamps stay on, and the front side markers blink opposite the tail lights. The rear side markers never blink... not sure if they should.

In the dash, i have an issue with the right turn signal bulb bracket. the bulb is fine. I can touch a 9v battery to it and it lights. if i put the bulb back in the bracket and touch the 9v to the electrical connections it doesnt light at all.

[greywurm]

Originally Posted by FirstOwner69

The one you are holding is the ammeter shunt wire. Is the battery post in the pic the negative post? Does the red wire going into the junction block from the back come from the positive cable clamp? If so, that would normally be a fusible link.

The wire in my hand goes to that post just to the left of it. It was initially disconnected when I got the truck. The other two red wires on that post, coming from the top comes from the positive post on the battery. On the bottom, comes from the splice on the driver side where the red wires of the alternator and regulator are soldered together. You mentioned this was factory and I agree.

[FirstOwner69]

Originally Posted by greywurm

No. It never moves.

Since it's dark out, I got to see my headlights at night since the improvements I made on wire joins... The head lights are brighter.

But I also noticed that my blinkers are odd... they work differently with the headlights on than the headlights off... maybe my issue is here?

hazard - tail, front side marker, and parking lamps blink together, both sides. timing is on then off immidiately, staying off for about one second. turn the headlights on, the parking lamps stay on, never off, and the blink pattern is longer. the front side markers stay on for about one second then off, then back on. The tail lights are on when the front side markers are off. I can also hear the clicks at a different rate.

left turn signal - headlights off, the pattern is longer than the hazards. stays on for about half a second, goes off then immidiately back on. if it stays on for a while, it eventually just stays on.

right turn signal - headlights off, it is slow... i think the battery is pretty drained now. All in all, when the headlights are on, the front parking lamps stay on, and the front side markers blink opposite the tail lights. The rear side markers never blink... not sure if they should.

In the dash, i have an issue with the right turn signal bulb bracket. the bulb is fine. I can touch a 9v battery to it and it lights. if i put the bulb back in the bracket and touch the 9v to the electrical connections it doesnt light at all.

When the battery is drained or not charging the flash rates will be slower, especially with the headlights on. The parking lights should always be on with the headlights. On some trucks, the front side markers blink with the turn signals. Others do not. That may depend on model year. For those that flash, I think when the headlights and/or parking lights are on, the side marker flash alternates with the flash of the tail and parking lights. With the headlights and parking lights off, I think they flash in unison with the tail and parking lights. The rate of flashing of 4 way hazards may differ from the flashing rate of turn signals since they use different flashers.

By signal bulb bracket, I assume you mean socket. It sounds like it may be bad, but run the test again with another bulb. Sometimes you just need to reposition the bulb contacts a bit before placing it in the socket.

I'm signing off for the night...

[FirstOwner69]

Originally Posted by greywurm

The wire in my hand goes to that post just to the left of it. It was initially disconnected when I got the truck. The other two red wires on that post, coming from the top comes from the positive post on the battery. On the bottom, comes from the splice on the driver side where the red wires of the alternator and regulator are soldered together. You mentioned this was factory and I agree.

Sounds right.

[greywurm]

Thanks for everything FirstOwner.

I do mean the socket... I tried a couple of the other bulb in the bad socket with no luck. I also tried the bulb on a couple other sockets and it worked, so I just need to track down a new socket.

From your reply, I take it that I am still at square one on the wiring issue and what I see with the lights are normal. Bummer. I may go ahead and order a harness and PCB from classic industries and resume this next weekend.

[FirstOwner69]

Originally Posted by greywurm

Thanks for everything FirstOwner.

I do mean the socket... I tried a couple of the other bulb in the bad socket with no luck. I also tried the bulb on a couple other sockets and it worked, so I just need to track down a new socket.

From your reply, I take it that I am still at square one on the wiring issue and what I see with the lights are normal. Bummer. I may go ahead and order a harness and PCB from classic industries and resume this next weekend.

Classic Industries also has sockets.
GM w/o bulb http://www.classicindustries.com/truck/parts/g2071.html
Repro with bulb http://www.classicindustries.com/tru...ts/cx1807.html

Jim

[greywurm]

Since the distributer was upgraded to HEI, I decided to compare shorty's FAQ on the conversion to how it was done on my truck. Appears to be ok, except shortly after his tutorial, there is a post talking about a white resistance wire that is split to two yellow wires, one for the starter and one for the dist. I checked mine, but its spliced from a tan wire that runs to the firewall, then inside the cab, its pink. I think its the pink wire to the ignition. Since it's a soldered splice, I am thinking its factory... is there a way to tell if the wire is resistance, or am I going down a useless road

[FirstOwner69]

Originally Posted by greywurm

Since the distributer was upgraded to HEI, I decided to compare shorty's FAQ on the conversion to how it was done on my truck. Appears to be ok, except shortly after his tutorial, there is a post talking about a white resistance wire that is split to two yellow wires, one for the starter and one for the dist. I checked mine, but its spliced from a tan wire that runs to the firewall, then inside the cab, its pink. I think its the pink wire to the ignition. Since it's a soldered splice, I am thinking its factory... is there a way to tell if the wire is resistance, or am I going down a useless road

I'm guessing that tan wire may be a resistance wire. Does it appear that the tan wire could actually be discolored white?

I converted my 350 to HEI. I read of 2 different ways to deal with the wiring. The easiest way is to run a 12 gauge wire from the distributor through an existing firewall grommet to the ignition unfused terminal on the fuse block. The other (and the one I used) was to replace the resistor wire to the under hood firewall bulkhead connector with a 12 gauge wire and abandon the wire that ran to the coil. I wanted it to appear factory. The 70s and 80s trucks were set up this way, and I used a pink wire and terminal from one of those trucks. Some folks added a fuse to the wire. Others did not. I did not.

Has your engine been converted to an electric choke? If so, as I recall, it should also be wired to ignition unfused. If it's wired to always on 12 volt, I'd think you'd have a constant power drain.

I have some links to several threads describing the conversion if you want to see them. Here's one of the better ones. http://67-72chevytrucks.com/vboard/s...d.php?t=148346 AND, post 13 in this one shows the resistance wire. http://67-72chevytrucks.com/vboard/s...d.php?t=536317

Also, if you order the harness from a vendor, it may be for a points distributor, so you may need to convert.

Somebody please correct me if I got this wrong on any of the above!

[greywurm]

It looks pretty tan, almost brown. I might just replace it. How do I get it in the firewall grommet? I'm out with the wife so I need to double check where exactly it goes on the inside of the cab. I was using that thread you linked for the HEI. Pretty simple. In my distributer, there wasn't an extra ground cable under the coil cap so I added one like the instructions but it didn't make a difference. Took it out for now because I couldn't get the cap back on. I think I need a differ spade jumper.

How would I know if I had an electric choke? I don't recall any wires around the carburator.

[FirstOwner69]

Originally Posted by greywurm

It looks pretty tan, almost brown. I might just replace it. How do I get it in the firewall grommet? I'm out with the wife so I need to double check where exactly it goes on the inside of the cab. I was using that thread you linked for the HEI. Pretty simple. In my distributer, there wasn't an extra ground cable under the coil cap so I added one like the instructions but it didn't make a difference. Took it out for now because I couldn't get the cap back on. I think I need a differ spade jumper.

How would I know if I had an electric choke? I don't recall any wires around the carburetor.

Select any existing firewall grommet and push the new wire through an existing hole from the engine side and route to the fuse block.

Not sure what the original choke setup was on the 6 cylinder engines. If there are wires to the choke housing (probably the same type black cap as used on the V8s) it would be electric.

[greywurm]

I'm turning in the towel and am going to get a new harness. I got in touch with a local guy that I actually think is on here and he can get me a full harness for relatively cheap. Sounds like a big project, but I think I will avoid some head aches. I'll post back once I get it in. Thanks for all your advice firstowner69. I couldn't have gotten as far as I did without your help.

[davepl]

My resistance wire was tricky - someone has replaced the last foot or so of it with yellow wire, so I thought the resistance wire had been removed when whoever did it installed HEI. But no, only the last foot. When I ordered the new M&H wiring harness I specified HEI so it came without.

Whatever you do, get a harness made for YOUR truck. Not bashing painless, they likely make a great product, but it's generic. Get the AAC or M&H one set up for HEI like I mention above. Remember you've got TWO harnesses in the front, one for the engine and one for the front (lights, etc).

Also remember that there are TWO little black fuses in the harness. Both of mine had caked for some reason and my ammeter didn't work.

[greywurm]

If I wanted to bypass the ammeter and wire in a dummy light, any one know how I would do that? If the ammeter controls the circuit and doesn't work,couldn't that be my issue? I'll post a pic of the ammeter shortly.

Here's the pic. The needle never moves. I'd use the light I circled. It is partialy hooked up to a sensor for the parking brake so it doesn't work.

[FirstOwner69]

Originally Posted by greywurm

If I wanted to bypass the ammeter and wire in a dummy light, any one know how I would do that? If the ammeter controls the circuit and doesn't work,couldn't that be my issue? I'll post a pic of the ammeter shortly.

Here's the pic. The needle never moves. I'd use the light I circled. It is partialy hooked up to a sensor for the parking brake so it doesn't work.

I don't know how you'd do that. I'm sure it's doable. However, as with all gauges, the ammeter only monitors the system and tells you what's happening. It tells you if the alternator is charging the battery or not and gives an idea of the rate of charge or discharge. It does not control the charging process. Basically, the voltage regulator controls your charging system as long as it, the alternator and battery are in good condition..

[davepl]

I converted my idiot-light dash to a rally (gauge) dash in my 2+2. While that was going from a Canadian idiot light cluster to a US rally cluster, wiring changes were required. I would imagine that if they could be made to use the same setup (PCB and harness and connector) they would have. But I think the idiot light took a different path on the PCB.

I can't tell you why, just what my experience was.

I also believe the ammeter and the idiot light provide some kind of resistance load to help excite the alternator. If you go to a one-wire alternator you lose that and they have to self-excite or be taken over a certain RPM to even start working. So the light does something useful.

Actually, that just reminded me! When I was a kid, circa 1972, the car's ALT idiot light would dimly glow now and then. Drove my dad crazy. He carried an alternator with him because he just didn't trust it. No one could ever find the problem, but it never manifested into any failure, just spooked us that the idiot light would light sometimes.

In the 90s I noticed somehow that when it did it, if you reached under the dash and grabbed the bulk of the harness, you could move it around and change the degree to which the ALT light was lit.

In the 2000s (and this is all the same car) I started a tear-down for restoration. When I pulled the fuseblock, one of the connectors between the engine side and interior side of the fuseblock bulkhead was just laying there and HAD NEVER BEEN CONNECTED from the factory. So if things moved or jostled one way or the other, they might touch, but never reliably.

Sadly my Dad had been dead for 14 years or so at that point. I really wanted to be able to tell him the solution to the decades-old mystery!

[davepl]

Back to your initial problem though, why not install a volt gauge instead? It'll tell you a lot more than either an ammeter or idiot light.

[greywurm]

So, waiting on getting info on a harness for the truck from a local guy. While I have been waiting, this has been eating at me... Anyways, the horn wiring seemed suspect to me (note not connected green wire near horns, but an additional green wire is connected in a post a few back).

I looked over the wire diagram and didn't see the button actually noted after the black cable goes to the steering column harness (the U shaped connector). After some reading, I see that the black wire should go to the horn button as it provides a ground for the relay. Correct?

It currently takes a blue / white wire to it with a wire going out directly to the second green wire that goes straight to the horns. That blue / white wire is spliced in with the cig lighter cable from the fuse block.

I haven't traced the black wire from the horn relay yet - its dark and runs into a wire bundle in harness tape that I haven't undone yet, but I think its safe to assume that it goes nowhere.

I did try disconnecting the relay to see if the was improvement but there was none... Are there aftermarket horn buttons that wire differently than stock, just providing ground to the circuit? Its not in the steering wheel but a separate button on the dash which I thought was stock...

My understanding of my problem is that there is an accessory pulling voltage from the circuit but not putting it back via a ground. So of it were the button, disconnecting its positive side from the fuse relay should stop it from pulling and not returning, thus correcting the issue... but it doesn't. Am I barking up the wrong tree again?