Ignition Switch Ground Melted

Hey Guys,

Took a look under my dash today to check if I still had a resistor wire at the ignition switch and found the ground burnt. Saw another owner also had a similar problem with the ground melting, any common causes for this? Mine looks like the picture below, but it's burnt after the connector. 

If not, any clues as to where that ground separates from the main harness after the fuse box? Really don't want to have to tear apart the whole harness...

Also does anyone see the resistor wire in the picture? I thought it was supposed to be a solid pink wire, but the closest mine are are red striped. Everything looks stock, but I get a full 12v at the coil on the run position...

Any help would be great!

Thanks,

Adam

That wire provides the ground for the steering column as well as the proof out circuit for the brake warning light. If a hot wire touched any part of the steering column the shorted load was carried by that small wire. The wire on the other side of the other half of the connector may be damaged, also.

The resistor wire is after the other half of the connector shown in the picture.

If your resistor wire is in place and hasn't been bypassed you have to test the voltage when the coil is “loaded“. Ground the negative terminal on the coil and then check the voltage on the positive coil terminal. Do not leave the ground wire on the coil for more than a few seconds with the ignition switch on, or the coil will get hot and may be damaged.

That wire provides the ground for the steering column as well as the proof out circuit for the brake warning light. If a hot wire touched any part of the steering column the shorted load was carried by that small wire. The wire on the other side of the other half of the connector may be damaged, also.

The resistor wire is after the other half of the connector shown in the picture.

If your resistor wire is in place and hasn't been bypassed you have to test the voltage when the coil is “loaded“. Ground the negative terminal on the coil and then check the voltage on the positive coil terminal. Do not leave the ground wire on the coil for more than a few seconds with the ignition switch on, or the coil will get hot and may be damaged.

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I had horn problems with my aftermarket steering wheel. It blew the fuse immediately and when I put another fuse in it just honked constantly, could this be that hot wire on the steering column you're talking about? EDIT: Actually now thinking back to it... I did have a spark fly one time with that horn and my steering wheel... That must've been it.

Regardless I will have to replace that ground wire, hoping to do so without tearing the factory loom apart and running a new ground outside of the loom. Do you know where the wire is supposed to be grounded too?

As for the resistor wire is it the pink and white one? I've read everywhere the resistor wire is pink, but all the way up at the coil the wire is red and green... EDIT I have a factory tach dash that was converted my rocketman if that makes a difference.



I've been running a petronix coil 40111, which is internally resisted... I wonder if I've been running the car double resisted? https://pertronix.com/pertronix-40111-flame-thrower-coil-40-000-volt-1-5-ohm-black-epoxy.html#.Xr4jI5NKg1I

Thanks for all your help Don, your posts have saved me a number of times.

Adam

7123's resistor wire was changed from pink from earlier years to a red/green wire.

To keep from burning your car up, in the future please remove the negative cable from the battery before working on anything that has an electrical component or any wire connected to it or running through it.

7123's resistor wire was changed from pink from earlier years to a red/green wire.

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Interesting, so the entire red/green wire is resisted? Or is there a section of resisted wire somewhere?

To keep from burning your car up, in the future please remove the negative cable from the battery before working on anything that has an electrical component or any wire connected to it or running through it.

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Ya the horn incident was about 4 years ago, have learnt since... This is just this first time I've had to look at the ignition switch since. 

So any idea where that ground goes? Otherwise I should be able to run a new wire ground wire to the column from any good ground correct?

7123's resistor wire was changed from pink from earlier years to a red/green wire.

Click to expand...

Interesting, so the entire red/green wire is resisted? Or is there a section of resisted wire somewhere?

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There are other, normal, red/green wires as well.  I dunno why Ford did this, but it does confuse things.  The resistor wire (for 7123's) goes from the green box on the rear of the fuse box to either the tach plug or to the fuse box itself.