HEI and Starter wiring?

[DBear]

Okay, on the wire harness in the engine compartment, the one that is used for ignition, starter, etc....my question is how do you wire HEI distributor and starter, etc....??? I know the short green one is for temp switch.

[McClinton527]

There should be a green wire coming from the firewall wire harness that you need to put a spaid terminal on to the HEI on the (BAT) side. Its a switched power source from the fuse block. The other terminal is simply for a tach. There should be a couple different green wires. Use a test light to determine which one is a switched power source, the temp one wont have any power. The starter is a heavy gauge red wire with a larger eyelit terminal on it that you shouldnt have to mess with. theres also a ground. As far as your one wire alternator goes you need to run one wire from the alternator to the battery to maintain the charge. and the other wire comes from the firewall and I believe is purple

[spike38]

Hope this helps.

Spike

[DBear]

Originally Posted by spike38

Hope this helps.

Spike

on this diagragm, it shows the red wire going to the distributor and the purple going to the starter....that is different than what McClinton had said????

[LostMy65]

Originally Posted by spike38

Hope this helps.

Spike

It helps tremendously!

Thank you!

[trebeck]

Exactly what i was looking for - thanks for the pics and detail, 05 crewcab.

[05crewcab]

Hey, no problem. Good Luck!

[cerjio]

Originally Posted by spike38

Hope this helps.

Spike

I have a question regarding the black fuseable link wire coming from the positive side of the battery goes to a juction box , an the black wire that shows a fuse inline . my question is this , i dont have a fuseable wire from the battery do I need this an where can i get one, also what size fuse goes into the inline fuse link ? I'm redoing several mistakes PO have done an dont know what to do here!

[cerjio]

I thought my previsou question would show the wire diagram

[spike38]

Originally Posted by cerjio

I thought my previsou question would show the wire diagram

I'm sorry, I missed that post. I'm going to my shop in the morning.
I'll check the size for you.

Spike

[spike38]

Originally Posted by cerjio

I thought my previsou question would show the wire diagram

mine is 4amp fuse

spike

[VetteVet]

Originally Posted by cerjio

I have a question regarding the black fuseable link wire coming from the positive side of the battery goes to a juction box , an the black wire that shows a fuse inline . my question is this , i dont have a fuseable wire from the battery do I need this an where can i get one, also what size fuse goes into the inline fuse link ? I'm redoing several mistakes PO have done an dont know what to do here!

If you look at the top of the top diagram you can see the fusible link and the wire with the fuse inline. This fused wire is for the battery charge gauge and works in conjunction with the one on the bottom of the diagram. If you have an idiot light you won't have these wires. The fusible link is nothing but a section of smaller gauge wire inside the wire that goes from the battery positive post to the terminal on the passenger side fender. It feeds and protects the entire positive circuit for the truck. If you don't have this then you are getting your positive voltage to the cab from somewhere else. In 1974 Gm started running the feed wire from the starter large post on the solenoid and the fusible links were moved down there.

The HEI feed wire can also be run from the firewall connector if you remove the orange/blue resistor wire and replace it with a 12 gauge red wire. It runs from the key switch ignition terminal to the firewall block. You can't just hook up the orange/blue wire to the HEI bat terminal because the HEI needs a full 12 volts to fire properly.

You guys can find out all this stuff if you hang out in the electrical forum.

[DBear]

I just looked at the harness, and the heavy wire seems to be the purple one....???

[05crewcab]

The diagram is correct.

Run a new 12ga wire from the ignition unfused terminal on the fuse block to the BAT terminal on the HEI (red wire above).

Then, there is a solid purple wire to your starter from the fuse box...keep this wire and the heavy + lead from the battery attached to the starter, and disconnect the yellow (it ties to a purple/orange resistance wire as well) from the starter and discard (not shown on diagram)

Follow the diagram and you are all set...only two wires and you'll be up and running.

[DBear]

Originally Posted by 05crewcab

The diagram is correct.

Run a new 12ga wire from the ignition unfused terminal on the fuse block to the BAT terminal on the HEI (red wire above).

Then, there is a solid purple wire to your starter from the fuse box...keep this wire and the heavy + lead from the battery attached to the starter, and disconnect the yellow (it ties to a purple/orange resistance wire as well) from the starter and discard (not shown on diagram)

Follow the diagram and you are all set...only two wires and you'll be up and running.

First of all, I want to thank you guys.....

when you say disconnect the yellow, that it ties to a purple/orange resistance wire from the starter and discard..??? can you explain alittle more for this wiring dummy????

[05crewcab]

Sure, in stock form, there are two wires from the fuse box that go to the starter. a solid purple wire, and a purple/orange wire. The purple/orange wire T's with a yellow wire before it hits the starter. that yellow wire goes to the coil for the old points distributor system. With HEI, there is no coil, so the yellow and purple/orange wires are not needed any more...you can just cut it off at the fuse panel and toss it. the reason for doing this is the puple/orange wire is a resistance wire, and will get super hot and melt if left connected with no coil.

Now, having all that said, the truck is 40 years old and has probably already been butchered a bit in the wiring department, so your wires may look different....as long as your finished product looks exactly like the diagram above you'll be set:

New 12ga to HEI from ignition unfused in fuse panel (red)
Existing 12ga to Starter from fuse panel(solid purple)
Existing 6ga positive battery cable to Starter from battery (Thick Red or Black)

[robzilla]

i'm doing the same upgrade, do i need to run the wire from inside the truck? i ran a wire for the electric choke for the carb from inside fuse box. not sure if there is another "keyed" terminal available inside. which one can i splice into? or should i use the only available terminal (that i used for the electric choke) only for the hei? and splice into something for the choke?

[DBear]

Originally Posted by 05crewcab

Sure, in stock form, there are two wires from the fuse box that go to the starter. a solid purple wire, and a purple/orange wire. The purple/orange wire T's with a yellow wire before it hits the starter. that yellow wire goes to the coil for the old points distributor system. With HEI, there is no coil, so the yellow and purple/orange wires are not needed any more...you can just cut it off at the fuse panel and toss it. the reason for doing this is the puple/orange wire is a resistance wire, and will get super hot and melt if left connected with no coil.

Now, having all that said, the truck is 40 years old and has probably already been butchered a bit in the wiring department, so your wires may look different....as long as your finished product looks exactly like the diagram above you'll be set:

New 12ga to HEI from ignition unfused in fuse panel (red)
Existing 12ga to Starter from fuse panel(solid purple)
Existing 6ga positive battery cable to Starter from battery (Thick Red or Black)

That makes sense now.....one question though, when you say "new 12ga to HEI from ignition unfused in fuse panel" ...are you talking about running a red wire from the fuse block in the engine compartment or from the fuse panel inside the truck? Also, when you say unfused, do you mean no inline fuse or something?? I know, I really dont know much about the electrical, but I will give hell trying.

[spike38]

here is a more complete wiring.

Spike

[spike38]

Sorry, that didn't work well.
Try this

Spike

[cerjio]

Thanks Guys I know about changing out the wire for the Hei an have done that an I have the fuse inline on the batter wire , showing a grey wire , but not sure of the two that come from the battery on the top of the diagram, just needed to know what wire to get an what size fuse to put in the other !