I just put a new motor in my 66 ss and had to replace all the wiring harnesses due to the previuos owners butcher work, and I'm getting some strange happenings. The temp. gauge is showing that the motor is getting hot but when the motors off and I turn the head lights the temp. indicator goes full scale. My blinkers come on and who all knows what else. I've checked connectors and grounds but still there. The only thing that I can think of is the grease like goo that was on the ends of the harnes plugs to the fuse block. Should that have been cleaned off, I thought it might be a non conductive lubricant.

Thanks

Donn

If you are talking about the bulkhead connector on the firewall, that "grease like goo" is there to protect it from corrosion. It's supposed to be there, so don't clean it out. Don't know what the problem is though.

Are the front fenders on right now when you try this? I suspect a ground issue, either from your dash, or from the engine not being grounded. My headlights and dash lights did some weird stuff until I had the front clip installed, as there was not enough ground.

I had a similar probloem after replacing all of my harnesses from the dash forward. My temp gauge & fuel guage would shoot all the way up when I turned the key on. I took the dash back apart, disconnected the harness from the gauge cluster, plugged it back in, checked all of the connections on the guages, reassembled everything and magically the problem was gone. Another problem I had was the dome light refused to work and it had worked before I replaced the dash harness. It turned out the new harness had one connector in the plug that didnt line up with the other connectors when plugged in. It took me an entire Saturday to figure that one out. Moved the connector over and the problem was solved. You can't always assume the new stuff is 100%.