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Discussion Starter · #1 ·
I have a 70 coupe all gauges worked except temp gauge. I recently replaced the temperature gauge but when I reassymelbled the fuel, temp and oil gauge no longer work I checked to make sure they weren't grounding out i taped the area of gauge posts that might be touching the housing, and replaced voltage regulator pried contacts of connector to ensure they were making good contact and I noticed that the purple wire in wiring harness labled number 11 is getting hot and the is a black wire that goes to nothing any ideas as to where it should go and why the purple wire is getting hot. Can someone give me suggestion as to what i should check, I see this problem posted in many forums with no solution Someone has had to have fixed it b4
 

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The violet wire (wire 30A) is a resistance wire that comes from the fuse block and powers the constant voltage regulator. Because it is a resistance wire, it is probably normal for it to get hot.

I'm looking at '69 wiring diagrams, and I see no solid black wire anywhere near the instrument cluster. Either it's creative wiring by a PO (which means you get to trace where it's supossed to go), you are not seeing the tracer color on it (clean it with lacquer thinner or equivalent), or the '70 is just different than a '69 (I know there is a LOT different between the 2 years ... this could be one of them).

I highly recommend getting a wiring diagram for a '70. I love the Pro Products ones, if you can still find them. They went out of business a few years ago, but all of their diagrams were bought by another company and reproduced.
 

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I noticed that the purple wire in wiring harness labled number 11 is getting hot and the is a black wire that goes to nothing any ideas as to where it should go and why the purple wire is getting hot.
does the black wire go into the same connector as the violet wire? I have a 69 and have spent a LOT of time looking at that connector recently. Mine has a black wire that goes into the same post as the violet, and right across from it, there's a post with two black wires. The 70 may be different, but on the 69, the side with the 2 blacks serves as a ground for one of the dash lights and the voltage reg., and the other side is the resistance wire to the + side of the volt reg. as JoHnPro said. The additional black wire is a mystery to me too. I assume it's running power to something else and connecting there as a junction.

Don't know if that helps any. I have mapped the plug with what's hot with key on/off, and headlight/park on. I can send it to you if it helps you any. Again, the 70 could be slightly different.
 

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Discussion Starter · #4 ·
Yes pleas edo i found someone who has two other wiring harnesses and had him look he stated they both have black wire and that it goes nowhere also. Strangest thing, i guess they ut it there to baffle me. LOL
 

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Discussion Starter · #5 ·
Also Does anyone have the wiring diagram that show the purple wire the ones I have do not show the purple wire in slot 11 I would like to track it to ensure it is not worn through and grounding anywhere.
 
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