What to do with leftover coil wires?

[Texas1971]

Changed over to hei but have two coil (?) wires that don't appear to be needed coming from harness. Since I'm not getting spark from the dizy, I was wondering if I should be connecting the leftover coil leads to something or just cap them off? Any help from y'all would be appreciated.

[Snew]

Mine were loose anyway from the tape deteriorating so I completely removed them from the harness. Clean and simple.

[Texas1971]

Thanks for the advice. I reckon the stock pigtail is the only hot line going into the dizy. So, if I'm getting juice there but none coming out of the wires, then maybe the cap and modulator are bad? Thoughts?

[glock35ipsc]

Since you are not getting spark from the new dizzy, it sounds like you need to run a new wire to the HEI that carries a full 12 volts. The wire running from the fuse block to the coil is a resistor wire, and only allows something like 7 volts to go to the coil. This needs to be replaced. An easy way is to run a new wire to an ignition-on tap on the fuse block. Or, take the harness apart and replace the original resistor wire with a new one. You won't need or use the original wires, you can cap them off.

[Texas1971]

Thanks Glock. I just assumed that the original pigtail with one power and one tach lead would work. The tach line is not connected, just taped off. ??

[glock35ipsc]

The tach wire will need to be one you run from the tach itself, I don't think there is a tach wire in the factory harness. Unless it was a big truck that came from the factory with a tach.

The original "+" wire to the coil should be yellow, and it runs down to the starter solenoid where it ties into the resistor wire, it's usually a multi-colored wire, something like purple/orange, orange/white, purple/white..... I can't remember exactly. The other wire coming off the coil is just a ground wire.

[Longhorn Man]

there were 2 wires going to the positive side of the coil.
A yellow one that offered a full 12 volts when starting. Remove this wire all together. There is no need at all for it anymore.
The other wire should be cloth covered, and goes into the harness, up to the bulkhead on the firewall. This wire can be cut off and replaced, or deleted all together and replaced with one to the IGN UNFUSED spot on the fues box in the cab.

[shifty]

It sounds like his harness came with two leads, tach and 12v. Wouldn't that suggest it is setup for HEI already, like maybe someone put in an aftermarket or upgraded harness?

Texas1971, what are the colors of the two wires? Is one of them wrapped in cloth?

[cstm68]

befor i did my painless kit i took all the coil wires out of the harness and the risistor when i did my hei
then i took a wire from the hei to a switched 12v sorce on the fuse block and it started right up!!
i am using an aftermarket tach so i cant help you there

[Texas1971]

great info folks!
BTW, it is not a brand new diz, but I do have 12v power going to the pigtail. I replaced the coil on the cap and still no spark. next will be the module and if that don't get it, I'll be back. I taped off the old coil leads.

[shifty]

Try running a direct line from the positive side of the coil, only for testing purposes.

also, make sure your coil is properly grounded.

i know there will be a lot of stuff you already know here, and your engine is probably a V8, but why not pop in and check out the writeup i did on HEI?

http://67-72chevytrucks.com/vboard/s...d.php?t=148346

pay special attention to the wiring, grounding of the coil, troubleshooting, etc. lots of info in there - you never know what may trigger in your head when you read it.

good luck!