question on HEI wiring ???

[1972_Buford]

I see the PO used a yellow or white wire from the original harness as a batt feed for the coil on the HEI. Is this enough? I read this has a resistor in it as well, could this be a cause of my stalling after it warms up? The wiring looks way too small and I believe it needs to be a #10 or #12 but it is way smaller than that and might be what originally powered the original coil setup.



As I am digging into this truck I am finding a ton of wiring nightmares. Any help is appreciated.

-B

[Shyguy]

This is how we did it. We ran a 12 ga wire with an in-line fuse from an unfused ignition connection on the fuse block. This way a true 12 volts is supplied to the distributor.

Some have said run a 10 ga wire with a 30 amp in-line fuse from the unfused connection on the fuse block, but we opted for a 12 gage wire.

We just taped off the yellow wire.

[1972_Buford]

Would you happen to know what issues I would run into with running that yellow wire? I am also chasing down a stalling issue that I suspect is in the Dizzy somewhere.

[Shyguy]

If it is the resistor wire it will not be supplying 12 volts. If it is not providing 12 volts to the distributor it could cause the ignition module to burn out. It would be easy to check the voltage with a voltmeter.

I tend to like to go a little larger when I use electrical wire than some.

[geezer#99]

THe yellow wire is attached to the resistance wire. A 3 way connection in the wiring loom. One end went to your coil + and the other end was on the I terminal on your starter. Make sure the yellow wire is also removed at the starter.

[1972_Buford]

I have not checked the starter yet for this. Is there a specific reason it should be removed or is it just obsolete?

[VetteVet]

Here is an excellent write -up on the HEI conversion. Take out the resistance wire and the wire from the starter and just run a 12 gauge red wire to the HEI distributor BAT terminal from the fuse panel IGN-UNFUSED terminal and you're done,
You could take the resistance wire out of the firewall block and run your 12 gauge wire from there since it comes from the ignition switch.
The second diagram is the one to go by.

............http://rmcavoy.freeshell.org/HEI.html

[geezer#99]

Originally Posted by 1972_Buford

I have not checked the starter yet for this. Is there a specific reason it should be removed or is it just obsolete?

If it's still there it could cause a short if the other end is grounded. It'll only be hot while cranking.

[mr48chev]

You can fold both the white wire and yellow wire over and tape the ends rather than removing either.

Most of us have run a 10 gauge wire from one of the two pins in the fuse block that are hot when the key is on.

This is going to be sideways to how it is in the truck but the two ign unfused pins on what appears to be the top row are the pins to pick from.
http://www.ebay.com/itm/SO-CAL-SPEED...item19d7f84167

Use a good quality female slide on that end and use the correct end to hook the wire to the Hei on the other end as a female slide has a tendency to loosen at inopportune times and kill the engine or cause a miss. Yes that is the voice of experience speaking.

[1972_Buford]

Yeah I got the correct female end for the HEI batt side. Just another wire spliced into it. I have some 12 ga and I got a inline fuse so I may just go to the box like said above. Funny I just found a wire connector to the unfused ign pins and it went to a wire just laying on top of the dash. Pure awesomeness.

[mr48chev]

OOPs the link in post #2 should have been



You don't need a fuse on that line and you want at least 10 gage if not 8 gage wire on it. 12 is too small and won't flow the needed power for the HEI.

[1972_Buford]

Thanks for all the quick replies. I got it all rewired and went ahead and put in an inline fuse just in case. I also bought a new module to see if that is what was causing my stalling out.

I will update everyone on that as well.

-B

[richards72chevy]

So do have to run the 30 amp inline fuse?

[1972_Buford]

I did just in case.