I had to replace the complete wiring harness in my 66 Mustang coupe due to a wiring melting problem. The whole harness has been changed but now when I turn the key on all the gauges are screwed up. The temp gauge flips over to hot, fuel gauge goes to full when the tank is empty. Anyone have any suggestions what could cause that?

 

ugh. I hope someone will be along shortly and good luck with the fix

 

Just a guess but maybe you fried the constant voltage regular attached to the instrument cluster.

It's purpose is to regulate the voltage to a constant 5v. It may be flaky.

 

What kind of harness did you use? Was it new or from a donor?

 

I had a painless harness put in but the guy really screwed up, he didn't even put the constant voltage regulator in and hooked the wrong wires up to the wrong gauges. I have since had it rectified by a guy from Bracebridge and it is working fine now. Thanks for your input.

 

I hate incompetent people, glad it's fixed

 

Painless "aint".

Ron Morris is a better system, but it's too late to tell you that now!
Perhaps others in the Future will read this!.

 

^^^ thanks for the tip. Painless living off their reputation a bit too much maybe?

 

I think that is exactly it. It's the only company I've honestly ever heard of with that type of product.