HEI BATT hookup help

[brad20653]

Whaqts the best place to hook up the power with key to ? For my eletronic ignition

[Longhorn Man]

On your fuse box there is a terminal that should read IGN UNFUSED. This is everyone's favorite place.
The large pink wire on the back of the ignition switch is also an ideal place.
My fuse box was getting full and my large pink wire was already wearing a crimp-on connector, so I did it.
Many of the magizines claim that the fuse box isn't made to handle "that kind of load", and insist that you should splice into the big pink wire.
However, some on on here did an amp reading on the HEI wire and said it isn't much at all. (15 amps maybe?)
Either way you go, you'll be set.

[FRENCHBLUE72]

Mine is hooked up to a green and yellow wire that run's across the top firewll guttere it was hooked up that way when I bought the blazer. I s that the correct way or should I change it?

[ddsmith]

Why not take the firewall connector apart, remove the existing resistance wire and using a type 56 connector and the 12 GA wire from the HEI put it right back into the original slot. This is by far the cleanest setup and the wire on the inside of the firewall connector is 12 GA.

Mine is hooked up to a green and yellow wire that run's across the top firewll gutter

The resistance wire is the feed to the old yellow wire which originally went to the coil and the starter. If you unwind the black tape on the wiring harnass you'll see where the resistance wire joins the yellow wire. If yours is still there the resistance wire is the fabric covered wire coming out of the firewall connector. This does not feed full 12V to the HEI if it is still there. You can do as was mentioned above. It is easy to do once you understand how the connectors are held in place. Do yourself a favor and get a few of the male and female connectors to place in your connector assortment. I got mine at NAPA. You may have some trouble finding them without knowing what they look like. I'll see if I can get the part number. Off the top of my head I think it was 700245 and 700247. I'll try and verify the numbers.

[cdowns]

LIKE HE SAID thats what i did , why have loose dangiling extra wires make it look factory

[Brad]

I made it look factory as well. You can get the connectors at NAPA.

[ChevLoRay]

I had to have a new harness for my truck (fried some wires, etc.) and M&H Fabricators (aka wiringharness.com) make harnesses with original colors, connectors and appearance. If you are running an HEI, like me, they'll modify the harness to fit the HEI, making it look factory. It has the large pink wire available for an electric choke, or whatever. Just a suggestion. If your harness is good, modify what you have. If not, here's an alternative.

[FRENCHBLUE72]

Is this the pink wire everyone is talking about???

[Longhorn Man]

The one I am talking about plugs into the back of the ignition switch and then into the main harness. I have no idea where it goes to, but if you were to do the upside down under dash boogie, you'll see it going to the ignition switch.

[ddsmith]

That 12 GA pink wire Longhornmail is talking about is the feed to the resistance wire and it goes to the fuse box and the ignition switch.

[shadetree]

The post about the fuse box not being able to handle the extra load is actually very accurate. The AMPREGE usage of HEI's is low, but the VOLTAGE demands are kinda high. Going through the fuse box is not goint to overload your fuse box, it will kinda dampen performance of the HEI, as the voltage going into the HEI from the fusebox will be a little lower than a more direct routing. The voltage drop won't be much, but every fraction of a volt the HEI gets, it uses to create a hotter, better spark. If you are not racing the truck, and you never have cold starting problems, going through the fuse box is ok, you'll probably never notice any difference. However, if you have a lot of high ele. demand accessories, or add some in the future, you may want to re-think all of the wiring on the fusebox (I did). hope I've helped

[Longhorn Man]

Thanks for clearing that one up Shadetree...When i first came to the board some one was asking about HEI wireing and I was flamed for saying the words 'propper way" and 'splice" in the same sentence.

[LonghornJeff]

Are all fabric covered wires resistance wires?

[ddsmith]

Shadetree,
That brings up an interesting subject. I don't want to hijack this post but this is relavent to the subject. This same problem arises from one wire alternators if I'm not mistaken. The one wire alternator senses voltage coming out of the alternator versus the normal setup sensing downstream in the system voltage. If large loads are placed on the one wire system it doesn't compensate as well to maintain 12V way down the line. I take it from your comment on the fuse box being inadequate for hi demand usage that you also believe that one wire alternators are also inadequate for the task at hand.

[ddsmith]

Are all fabric covered wires resistance wires?

I believe the answer to this is no. Someone else may come along and correct me but the wire on my truck that went to the A/C clutch was fabric covered and I'm pretty sure it wasn't a resistance wire. It did however run above the passenger side exhaust manifold which may explain the covering. The easiest way to verify it is to disconnect both ends of the wire and check it with an ohm meter. Sometimes easier said than done because of the wire routing and the black harnass tape.

[ddsmith]

I must be getting old. The correct NAPA part number for the TYPE 56 connectors is 725145 and 725147.

[shadetree]

ddsmith, I don't like one wire alternators for other reasons, but, thanks, cause now I have one MORE reason not to like em. This post is getting interesting, and, yeah, response is a good issue to consider. But, all these issues are dead, IF the truck is not raced, and/or not being pushed to the limit in other eareas (a super-dee-duper sound system is a good example of pushing these electrical devices to their limits). After designing and installing MY super-dee-duper sound system, I re-did my entire electrical system (and, yeah, I race my truck occasionally). A one wire alternator only LOOKS cool, a much more practacle choice would be a 100 amp regularly wired alternator IMHO

[BobbyK]

One wire alt's put out 14.2 volts at the alt.only.

If demand increases in the system(A/C,high beams,heater on high) the one wire alt's will only maintain the 14.2 at the alt.

With all those accessories on the available voltage will drop and the one wire will not compensate for the increased load.

A 3 wire,or orig.GM alt., will measure the load on the system and will pump out more juice to compensate for the increased load in the system.
GM called it remote sensing.

That's the blue wire in terminal # 2 on the alt.

ddsmith,the A/C wire is a dark green wire and is only COVERED with a with a protective fabric.The wire itself is a reg. 14 gauge wire.

I wired my HEI directly from the PINK IGN. wire at the ign. switch.
This switch receives full battery power.I spliced into the large Pink wire and ran that wire through the firewall directly to the HEI.

wireing can REALLY suck!:p

[ddsmith]

BobbyK,
Thanks for the clarification on the one wire. It is like I thought but you said it nice and clear. Take a look at this below and correct me if I'm wrong.

I wired my HEI directly from the PINK IGN. wire at the ign. switch.

My point is that if you disconnect the bulkhead connector and pull out the resistance wire type 56 connector. You then have a feed that is the same as you have without the extra wire. That pink wire you are talking about is also the wire that connects to the passenger compartment of the bulkhead connector and feeds the spot where the resistance wire was connected.

Anyone needing more information/clarification just ask.

[BobbyK]

I should have clarified what I did.

I have removed the resistance wire all together.Actually I have removed that whole circuit that goes through the bulkhead connector.The circuit that normally has the resistance wire in it and would feed the HEI.

I'm useing that circuit now to power a 3 wire o2 sensor for my TPI.
I"ll actually will be attaching that Pink bulkhead wire to a terminal block as a IGN. on power source for the engine bay.

Who know what I'll be adding to this truck in the future. :p

[LonghornJeff]

ddsmith...thanks why I ask was Jewlz has her HEI hooked up by the ing to batt on the HEI and it is a fabric wire. It had me worried at fine69,s but it should be ok.
We all hope!

JEFF

[ddsmith]

LonghornJeff69, you said

Jewlz has her HEI hooked up by the ing to batt on the HEI and it is a fabric wire

I'm a little lost in the translation. This looks like shorthand and I'm not getting it. If the wire going to the batt connector on the HEI is fabric covered I would definately check and see if this wire is coming from the bulkhead connector because that was the original feed to the coil which is a resistance wire. Unless someone pulled out the resistance wire and replaced it with normal wire and put the fabric back on it. Maybe Jewels can let us know what she has so we can make sure she is getting a full 12 V supply to the HEI.

[LonghornJeff]

The fabric wire is a new wire installed at fine69s when she
switched to HEI. it runs from the fuzebox to the HEI.

[ddsmith]

I got it now and I understand why you ask. It sounds like her setup is fine. It should keep her going strong. Did she have a spare module with her? It never goes bad when your at home and the parts stores are open.