HEI question
 

Old blue has an HEI in it from the previous owner.
And it's a 20 gauge wire from an unknown source.

Anyways it broke off at the clip on my way to work Sunday, wired a temporary terminal end and went off to work.
And for a more permanent solution could I use a relay to operate the hei distributor?

Re: HEI question
 

Ensure any resistance wire or ballast resistor is no longer present and use 12 gauge feed wire to the HEI power connection (all the way thru from ignition sw) and ensure full 12V present.

EDIT: also, recommend look at VetteVet's posts on this thread.
http://67-72chevytrucks.com/vboard/s...d.php?t=648300

Re: HEI question
 

As long as it provides 12 volts to the hei when the key is on it should work. 20 gage seems a little light.

Re: HEI question
 

14ga minimum. Can terminal into the same plug as the original resistor wire that came out of the firewall.

Re: HEI question
 

I was thinking 12 or 14g wire at least.
Was curious if there was any reason not to relay it and take the load off a 52 year old ignition circuit.

Re: HEI question
 

There's no reason you couldn't use a relay in the circuit.

Re: HEI question
 

Depin the resists wire in harness pin in a new HEI lead. Works every time! Stop
By I’ll help you out

Re: HEI question
 

You should've seen the mess I took out with a new to me cluster.
The other one was a disaster :devil:

Re: HEI question
 

I've had mine hooked to a relay for years.
Gives you some options for security.

Re: HEI question
 

There's no issue with running a relay.

Re: HEI question
 

I feel that adding a relay only adds one more thing to fail to the circuit. There are millions of HEIs running around without a power relay with no problems.
If you decide to remove the Resistor/Ballast wire here is a link to how I did mine. Scroll to post 387.


https://67-72chevytrucks.com/vboard/...698377&page=16

Re: HEI question
 

I've read it only pulls 2-3 amps. Maybe I will have caddy help me re-pin it.

Re: HEI question
 

I used a relay because the painless harness had a smaller distributor feed wire than I was comfortable with. The relay is on the firewall, with heavier wire, and the path to the HEI is shorter now.

Before long the only original thing on the truck will be the rust.

Re: HEI question
 

Well, some multi meter testing showed 11.9v at the hot wire 12.5v at the battery.
14.2v at idle 13.6v at the distributor.

Got a new clip installed and going to leave it for now

Re: HEI question
 

:agree: He is absolutely correct top to bottom.

Re: HEI question
 

I have heard they should have about a 7.5 amp fuse. Have not had one blow yet and going to step it down to 3-4 and see what happens.