Electrical Gremlins

[vangremlin]

Pepe has been parked for the last week with electrical problems.  Here is the sequence of what's gone on so far.

1.  Last Friday morning, Pepe wouldn't start, no clicks, no turning over.  And when I turned the key to off some of the lights would stay on, like the charging light, seat belt light. I didn't have time to mess with it.  When I got home from work, still wouldn't start and the battery was dead.

2. I guessed it was the ignition switch, replaced that Sunday morning, no change in the problem.

3.  Did some further diagnostics, discovered the solenoid was bad - it was telling the car that the key was on all the time.  I realized this when the backside tab showed voltage even when the key was off and I had pulled the wires from the tabs off the solenoid.  I replaced the solenoid, eliminated the "always on" problem, but still wouldn't start.

4.  I put in a wire from the neutral safety switch post on the solenoid to ground, and it started fine.  However, when I turned the car off and came back around the front, there was a wire that was so hot that the tape around the wire bundle was smoking and it was melting some of the insulation on an adjacent wire.  The wire is marked with the blue tape in the photo, and at the time it formed a loop with itself, not sure if that was part of the problem.  The wire is a light red with a green tracer, and goes to the back tab on the solenoid.

Today I started to remove the neutral safety switch.  I tested it using the method in the TSM and there was no continuity between the center terminal and the transmission body.  I'm going to have to pull the front drive shaft to access the switch, and I'll probably have to hot wire the car so I can work on it in the garage rather than the street.  It's already 90 here, going up to 102, so I have a limited working window.  I'm open to any thoughts or suggestions on what might be causing the extra hot wire.  Thanks

[carnuck]

There should only be continuity between the center pin and the case of the trans in park or neutral. Has anything been changed recently? Stereo? Fog/driving lights? If not, and you have tilt steering, the wires may have frayed at the pivot point of the column and touched each other and/or ground.

[vangremlin]

Thanks Carnuck.  Nothing added recently and no tilt steering.  I thought I had the problem solved yesterday, it looked like there was a possible short on one of my older modifications which could have caused the solenoid and neutral safety switch to go bad.  Fixed that and got everything replaced.  Car was running fine for a bit, then I noticed the same wire was getting hot, I jiggled some wires then it was fine, I jiggled the same wires again and the car died, now nothing happens when you turn the key - no warning lights, no radio, no nothing.  The search for the problem will continue when I have some time and its not too hot.

[captspillane]

The circle connectors that feed the ignition often wear out. They form a circle that shares the solenoid post with the battery connnection. All of those, in every Eagle, should be cut a few inches away from the original circle connector and a new piece put in.

The wire they chose for that spot looks different than the others, its very flexible and soft. The wire often fatigues and breaks right before the connector. Its even more annoying because the ends of the wire inside the sheath touch sometimes, but then stop touching as soon as you wiggle it. It can be a very hard problem to track down.

[carnuck]

The circle connectors that feed the ignition often wear out. They form a circle that shares the solenoid post with the battery connnection. All of those, in every Eagle, should be cut a few inches away from the original circle connector and a new piece put in.

The wire they chose for that spot looks different than the others, its very flexible and soft. The wire often fatigues and breaks right before the connector. Its even more annoying because the ends of the wire inside the sheath touch sometimes, but then stop touching as soon as you wiggle it. It can be a very hard problem to track down.

Most of those are fusible links.

[vangremlin]

I've been working on it this morning, and it seems to be a bad connection coming through the firewall.  I'll probably run off to the junkyard and grab the harness that's in that 80 coupe.

[vangremlin]

Ok, here is the latest on Pepe's electrical gremlins.  The problem remains that, intermittently, the reddish/pink wire with tracer that connects to the left hand top post on the starter solenoid gets very hot.  It doesn't do it every time you start the car, more like 1 in 5 times.  Yesterday I put an ammeter in between the post and the red wire to monitor the current flowing through the wire.  Its hard to judge, because the scale on the meter is -60 to +60.  However, when the car is behaving, there is almost no current flowing through the wire.  However, occasionally it will misbehave, and it looks like there is less than 5 amps of current flowing.  But that amount of current makes the wire too hot to touch.  And if it is going to misbehave, it does it as soon as you start the car - it never seems to misbehave after the car has been running for awhile.  And, if it is misbehaving, if I shut the car off, and restart, its back to behaving.  I've replaced the ignition switch (that mounts on the column), the starter solenoid, and the neutral safety switch.  The last two got burnt out the first time it misbehaved, back before I knew there was a problem.

Looking at the wiring diagram, the reddish/pink wire joins with a yellow wire in the engine compartment, which goes to:

1) The idle speed control box on the inner passenger fender.  Since I no longer have a Carter carb I don't think this even comes into play anymore, and unplugging it has no effect on the hot wire problem

2) The wiring harness into the car, and is labeled wire "AV" on the wiring diagram at the junction between the inside and the engine compartment, where it splits to

  a) The ignition switch, or
 
  b)  the fuse box, where it looks like it supplies power to the instrument panel

My guess is that there is something goofy going on at the ignition switch, since the problem only pops up when you're first turning the car on.  My next step will probably be trying to adjust the switch, or looking for any obvious wiring problems in that area. 

Thoughts and suggestions are welcome.  Thanks.

[eagleman]

Don't have a answer for ya but wish I did my friend.Never the less it will be interesting to see what you find.Wishing you all the luck in the world. Sure sounds like a strange one that has me scratching my head.

[rollguy]

I believe the wire in question (red wire with tracer) is the resistor wire for the ignition.  That might explain why it gets hot.  When the starter is engaged, the solenoid puts a full 12v to the ignition (via green? wire).  If you do an ignition upgrade (big cap), you can delete the resistor wire from the system and just use +12v from the IM (yellow wire).  The coil would need to be changed to 3 ohm.

[Draekon]

I agree with Rollguy, it sounds like the hot wire in question is the coil feed wire.

Also, with your eagle being an '81, it shouldn't have an idle speed control module (unless its a California car).

[carnuck]

Could it be improperly hooked to something else? If the solenoid connections are corroded, the main power could be passing through it instead of the proper route. Loose connection can cause that too. I'd start by cleaning all the connectors at the solenoid.

[vangremlin]

Also, with your eagle being an '81, it shouldn't have an idle speed control module (unless its a California car).

It definitely has the idle speed control, but not a CA car.  Its an original CO car, set up for high altitude - maybe that's why it has the idle speed control module??

[ammachine390]

Also, with your eagle being an '81, it shouldn't have an idle speed control module (unless its a California car).

It definitely has the idle speed control, but not a CA car.  Its an original CO car, set up for high altitude - maybe that's why it has the idle speed control module??

All 81 Eagle's had the idle speed control. It was the California models that got the feedback carburetor as well though.

[vangremlin]

I believe the wire in question (red wire with tracer) is the resistor wire for the ignition.  That might explain why it gets hot.  When the starter is engaged, the solenoid puts a full 12v to the ignition (via green? wire).  If you do an ignition upgrade (big cap), you can delete the resistor wire from the system and just use +12v from the IM (yellow wire).  The coil would need to be changed to 3 ohm.

Thanks to everyone for their suggestions.  Rollguy, I'm not sure I'm following you.  I did the big cap upgrade years ago, and the yellow wire that is on the same post as the red w/ tracer is the one that got cut as part of that upgrade.  The red w/tr is labeled as the resistor wire and hooks onto a yellow wire that goes to the actual ignition switch.  What is the purpose of the resistor wire?  Are you saying that because I did the big cap upgrade I may not even need it?  Thanks again.

[vangremlin]

Are you saying that because I did the big cap upgrade I may not even need it?  

Well I just took the red wire w/tr off the solenoid and the car started right up...maybe its not needed.  Any concern that whatever was causing it to heat up occasionally might need fixing also?  Thanks.

[Draekon]

I believe the wire in question (red wire with tracer) is the resistor wire for the ignition.  That might explain why it gets hot.  When the starter is engaged, the solenoid puts a full 12v to the ignition (via green? wire).  If you do an ignition upgrade (big cap), you can delete the resistor wire from the system and just use +12v from the IM (yellow wire).  The coil would need to be changed to 3 ohm.

Thanks to everyone for their suggestions.  Rollguy, I'm not sure I'm following you.  I did the big cap upgrade years ago, and the yellow wire that is on the same post as the red w/ tracer is the one that got cut as part of that upgrade.  The red w/tr is labeled as the resistor wire and hooks onto a yellow wire that goes to the actual ignition switch.  What is the purpose of the resistor wire?  Are you saying that because I did the big cap upgrade I may not even need it?  Thanks again.

If you replaced the coil with a 3ohm coil (like the petronix one), then the resistor wire isn't needed and gets bypassed.  If you are using a lower resistance, 1.4ohm, coil, then the resistor wire is still needed so that the ICM doesn't get burned out.

[rollguy]

If you replaced the coil with a 3ohm coil (like the petronix one), then the resistor wire isn't needed and gets bypassed.  If you are using a lower resistance, 1.4ohm, coil, then the resistor wire is still needed so that the ICM doesn't get burned out.

Exactly.  The yellow wire provides power for the IM, and your new coil (3 ohm).  The resistor wire can be abandoned.

[Draekon]

Also, with your eagle being an '81, it shouldn't have an idle speed control module (unless its a California car).

It definitely has the idle speed control, but not a CA car.  Its an original CO car, set up for high altitude - maybe that's why it has the idle speed control module??

All 81 Eagle's had the idle speed control. It was the California models that got the feedback carburetor as well though.

I guess I just haven't looked under my hood recently.  I was basing that statement on the wiring diagrams I have.