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Old 08-16-2017, 11:25 AM   #1
Jayman931
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Ignition Coil Resistor Wire Problems

Electrical problems again

(I have HEI not points distributor)

SHORT VERSION: My rear turn signals and brake lights do not work. I thought I had fixed this problem but had the same wire short out again. It is the Ignition Coil Resistor Wire. I didn't know this at the time so I cut the shorted part out and replaced it. Now my starter wont disengage after engine fires up.(voltage not dropping) and I have no brake lights or turn signals (original problem).

Questions: 1) Where can I get a resistor wire...or how do I solve this problem
with the starter not disengaging after the engine fires.
2) Is this 2 unrelated problems or are one of the other 2 wires
that were ran with the coil wires turn signal/brake lights?


LONG VERSION
Awhile back I had no rear turn signals or brake problems....I thought I had it fixed when I found 3 wires that had been fried together (one was the coil resistor wire...the three wires were all ran in the channel where the back of the hood meets the body of the truck (kinda by the windshield spray nozzles)

I separated all the wires....put a heat shrink insulator on the Coil Resistor wire (that was the one that was shorting out to metal on the body) put it in a black plastic wire loom and everything worked for about a month.

Fast forward to yesterday. Rear turnsignals and brake lights do not work but rear running lights still do. I checked the three wires I had thought I fixed and they were worse than before. The loom was melted to the wires in multiple spots. At this point I decide I am going to run a new wire to replace the one that shorted out (which happened to be the Coil Resistor Wire...I didn't know this at the time)....So I cut a good bit of the wire out where it had been melted to the loom and reconnected everything. Annnddd...not only do the rear lights not work.....but the starter will not disengage when it starts. (I found out that this is cause the wire I put in isn't a resistor wire so the starter voltage isn't dropping from 12 to 9v.

Questions-
1- Where do I find a resistor wire....or is there any certain gauge or wire I can buy to fix this problem. This is my daily work truck.

2- Why do the 3 wires running from the firewall behind the master cylinder ....then running in the channel at the back of the hood and running down by the starter have anything to do with my rear brake lights and turn signals?

Sorry for the long post. I can take pictures upon request.
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Old 08-16-2017, 11:56 AM   #2
Jayman931
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Re: Ignition Coil Resistor Wire Problems

I have been researching more....can anyone confirm that I can remove the Resistor Wire and hook up a Ballast Resistor (1.6 Ohms)....

If so do I have to run this from the ignition? or can I start the wire at the fire wall?
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Old 08-16-2017, 09:19 PM   #3
franken
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Re: Ignition Coil Resistor Wire Problems

HEI wants a switched 12V supply and doesn't want resistor wire or a ballast resistor.
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Old 08-16-2017, 09:55 PM   #4
Ewr101
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Re: Ignition Coil Resistor Wire Problems

Frankenstein is correct, an HEI distributor has to have a full 12volts to operate at its best. The resistance wire should be taken out and a new, correctly sized, wire ran either from the junction block where the resistance wire was coming from or from the Ign.Unfused port on the fuse block. The distributor wires and rear lighting wires shouldn't be together up on the cowl gutter I don't believe. If I were you I'd trace out the rear light wiring from the tail lights to the junction block on the firewall to make sure they're ok. Then trace the distributor wire back as well. They might be in contact further upstream where they come thru the firewall.
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Old 08-17-2017, 12:20 PM   #5
Jayman931
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Re: Ignition Coil Resistor Wire Problems

Quote:
Originally Posted by Ewr101 View Post
Frankenstein is correct, an HEI distributor has to have a full 12volts to operate at its best. The resistance wire should be taken out and a new, correctly sized, wire ran either from the junction block where the resistance wire was coming from or from the Ign.Unfused port on the fuse block. The distributor wires and rear lighting wires shouldn't be together up on the cowl gutter I don't believe. If I were you I'd trace out the rear light wiring from the tail lights to the junction block on the firewall to make sure they're ok. Then trace the distributor wire back as well. They might be in contact further upstream where they come thru the firewall.

I installed the HEI myself. I connected the power to the HEI directly to a constant 12v wire near fuse box.

The resistance wire is still connected from the ignition to the starter, correct? Wont I still need it (or a ballast resistor) or the starter wont disengage when the engine fires up?
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Last edited by Jayman931; 08-17-2017 at 12:25 PM.
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Old 08-17-2017, 09:05 PM   #6
SuperChief
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Re: Ignition Coil Resistor Wire Problems

I think you need to investigate what is the resistor wire versus solenoid wire. If you are not a purist study up on Ford solenoid remote starting. Later in life the Ford conversion will save you from missed hot starts. I am an old newbie that reads this stuff. worth a look-see
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Old 08-17-2017, 10:14 PM   #7
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Re: Ignition Coil Resistor Wire Problems

Quote:
Originally Posted by Jayman931 View Post
The resistance wire is still connected from the ignition to the starter, correct? Wont I still need it (or a ballast resistor) or the starter wont disengage when the engine fires up?
No, the resistance wire (or ballast resistor) has nothing to do with engaging the starter and/or allowing it to disengage once the engine has started.

The only reason the coil/ignition circuit is even connected to the starter solenoid is to allow the solenoid's "R" terminal to provide full battery voltage to the coil while cranking the engine. That temporarily bypasses the resistance wire (or ballast resistor) for a hotter spark while cranking.

The circuit that engages the starter solenoid is typically a purple wire that is connected to the solenoid "S" terminal. That wire runs back to the "S" or "SOL" terminal on the ignition switch and might pass through a neutral safety switch along the way. This circuit should only have power when the ignition switch is turned to the "start" position.
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