I installed a 6 gauge cluster from JME today. It has a speedometer, tach, oil pressure, voltage, temp and fuel gauges. I started the car up and all of the guages appear to be working. The tach moves as you accelerate, etc. The blinkers work but the high beam light does not.

What really puzzles me is that all of the guages stop working (go to zero) when you turn the car's headlights or interior lights on. It doesn't affect them if you open a door and the interior lights come on.

Any ideas of what I should try?

 

forgot to add.....the car is a 1965 mustang fastback with a 1966 wire harness.

 

Sounds like the 12 volt power source for the gauges has been wired to the lighting power source; or there is some other cross wiring on the various 12 volt inputs.

If you did the wiring, go back and double-check the wiring to the cluster against the JME and Mustang wiring diagrams. If someone else did it, have them sort it out!

Good luck!

 

The problem has been fixed, thank you. It ended up being a problem with faded colors on the old wire harness. I just went back and rewired everything using a magnifying glass to see the colors (and a second opinion occassionally).