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Melted through wiring - advice needed

garvinogarvinoMember
I recently was under my dash finishing running some wiring for my remote power door locks (I will post some pics of the remote locks after I get this issue solved).

To my shock I found a light blue wire under the passenger side dashboard that had it’s sheathing melted. Some areas off the wire were 100% exposed. This wire runs into the wiring harness that is down near the main fuse panel. It also had a plastic connector that could be unplugged.

I unplugged the wire and cut a piece of the wire back and have been attempting to see where the wire runs and why it shorted out or burned through or whatever. I also have looked at DeTomaso’s wiring diagram trying to trace the wire.

I have concluded that one end of the wire runs to the ignition coil and the other runs under the dash towards the driver’s side. I have pulled the tachometer (a feat in itself – hope I can get it back in with my large hands) and can see the melted light blue wire behind the large wiring harness running on the driver’s side but cannot see were it ends (the light blue wire is totally bare on the driver’s side).

The wiring diagram shows this light blue wire terminating at the ignition switch after running through a connector block. It also lists the wire when it reaches the connector block as a “resistor cable 1.4 ohms”. I have included some pics below of the wiring diagram and where the light blue wire runs. I also have included a pic of the wire with the connector on the bottom that I removed.

Does anyone know where the connector block is actually located in the car? I am guessing it may be under the plastic surrounding the steering column.

Also has anyone ever run into this situation before? I verified that the light blue wire does go to the coil as the car will turn over and fire but will not stay running with the wire unhooked and cut out. I can jump power to the coil and get the car to run.

I am very concerned about why this Light Blue wire would have melted through. I am sure I would have smelled this if it would have happened while I was driving it. I also have a battery disconnect on the car which is always utilized.

Sorry this is so long winded but any help or advice would be much appreciated.

Thanks again.

Devin

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garth66garth66"When speed is the only thing that counts"
See this page for a picture of the wire connector block located above the steering column.
http://www.banzairunnerpantera...s_ignitionswitch.htm

The original connector (the black one in the pictures) has screws that grind directly into the wire strands, shearing many of them resulting in a poor connection with lots of resistance - note that the connector was beginning to melt on one side (I've seen others that were much worse!). I replaced it with a proper connector that has a sheath that clamps down on the wire strands without breaking them, creating a much more positive connection without the resistance of the old connector.
panteradougpanteradougMember
male. Makes the column "plug and play".

It wouldn't be a bad idea to consider the P-E ignition switch controller at this point either.

These ignition switches get funky with age. You don't want all that current running through the switch itself any more.

I already had to replace mine. They ain't cheap. "One bitten twice shy babe".

There are no irreplaceable semi-conductors to fail in the P-E components. It is different technology. I THINK Jon called it "fast technology"?

http://pantera-electronics.com/isc.htm

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garvinogarvinoMember
Garth, Doug, and Larry - thanks for all the fast responses. I am always so impressed with all those willing to help out on this forum - makes it great place.

I will tear into this project hopefully this weekend. Lately, it seems like one step ahead two steps backwards on my Pantera. I guess that is the way it goes, but I am glad I found this issue with the wiring now instead of after my car was on fire.

Any thoughts on pulling my dash out so I can get a better look at the rest of the wiring? I know it is quite a project but I can't help but wonder if any other gremlins exist under there.

Once again, any advice or suggestions are much appreciated.
panteradougpanteradougMember
What Larry W says is accurate. You can overheat the coil and resistance wire as a result IF you leave the ignition on and the car not running.

Those visionary folks at P-E anticipated this and once you put in their Ignition Switch Controller you can no longer do that.

I have to admit I killed a few coils in my time as a result of working on the car with the switch in the run position.

The ignition switch controller protects me from myself as much as anything else. I swear at times you can see me giving off sparks in the dark. Electric personality. That's me, or is that electriphiling personality? Maybe self-electrifying? Careful...don't touch that red wire over there ok? Wink
larrywlarrywMember
quote:
Has the same thing happen. Scary part was the amount of damaged wiring in the wire run in the rocker. Portions of the wiring had no insulation left at all. Amazed the car ran at all. Believe the PO wasn't using a ballast resistor.


That's why I asked if the LB wire on the engine side of the connector Garvino shows was melted. If not, I'd guess that the bullet was dodged.

In the later cars the 1.4 ohm ballast wire replaced the engine bay ballast resistor, but you bring up another point, if you do run points and a coil and choose to adopt the relay circuit shown, a ballast resistor will be required between the relay and your coil.

Even if you have some other form of ignition, that little circuit is a good way to feed it.

If you choose to use a stock style ballast resistor, as found in the earlier cars without the ballast wire, you will see it has 4 terminals, it will work, but you'll have to get an ohmmeter and find the two pins reading closest to the 1.4 ohm value and use those. Or else go to the oldest parts store in town, find the guy that's been there forever and tell him what you're looking to do.

Removing the dash is a chore, but it's an opportunity to chase down every bit of PO added wiring and finally figure out what they were trying to accomplish. Also a chance to replace that heater blower motor that's been acting up.

Good luck.
bosswrenchbosswrenchMember
Garv, if you have a copy of the Pantera Service Highlights (lite blue cover), it outlines with illustrations how to pull a 2-pod dash. You don't need to do every step in the manual. Mine has been off 3 times and pulling it is simple; putting it back is what takes time. The dash need not come completely out of the car, either. The last time, I simply twisted it a little and left wires from the e-flasher connected while I worked from the passenger seat (on the AC) with the dash above my shoulder. The unbolted steering wheel/column sets in the drivers seat anyway.
garvinogarvinoMember
Larry,

The light blue wire heading towards the engine harness area after the white quick connector (still near main fuse box under the dash) shows no evidence of melting (at least as much of it as I can see before it disappears into the loom). As you said, hopefully I dodged that bullet.

As for pulling the dash, I was just concerned about other wires that may have been secondary casualties that run next to and through the light blue wire.

Thanks for the input Bosswrench. I kind of figured that the dashboard, like a lot of parts on the Pantera, probably is no to bad to pull but a bearcat to put it back in. I also have a single pod dash versus the double pod - so I did not know if that added any different steps or challenges.

If I pull the dash maybe this would be a good time to add an extra AC vent in the dash (I think David B did that in his GT5 - if memory serves me correct) and also cover it leather.

Thanks again for all the advice. It is much appreciated.

Devin
panteradougpanteradougMember
DON'T pull the dash UNLESS you positively HAVE TO!
Theoretically it is no big deal. The reality varies accordingly.
The dual pod IS easier than the single pod by A LOT!

It definitely is not intended for humans to do this. There MUST have been special tooling for the factory back then. Had to have been. Roll Eyes

The biggest problem FOR ME is that the speedometer cannot be mounted to the dash before re-installation BECAUSE there is a mounting bracket for the dash to the car body directly behind it and the only way to access that is through the speedometer mounting hole.

That makes re-mounting (getting the inner nut on the speedometer) the closest thing to impossible that I have ever seen.

I AM STILL trying to figure that one out. I may have to fly in Bosswrench to do it for me? He knows the secret. Wink
Last edited by panteradoug

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