Hey all,

So I want to make sure I did this right. I went by the wiring diagram on GMC Pauls web site, and hooked up all bulbs for my new gauges to the grey wires in my factory harness. Then I hooked all the grounds to the ground wire in the harness. Nothing, no lights at all. I never drove the truck before I started the restification so I have no idea if the original gauges lit at all. I would bet not based on the bulbs I pulled out of the panel though. So, my question is am I doing somehing wrong? Is there a trick to getting aftermarket gauges to work off of the wire in that harness?

Thanks,

Orlando

you need to test the wires and see if they truely are 12v+ and ground. make sure that the harness ground is actually grounded to the frame and battery. Is the gage cluster grounded to the dash? Apply power to the bulbs to see if they light.

In other words prove all the components works, prove that the light bulbs light and the ground wire is grounded and the 12v power has power. a cheap ohm meter and a test light should get you thru it.

I'm not sure what year your working on but there is a very good incolor wiring diagram somewhere on this site you can trace curcuits with

well its actually the sticky at the top of this forum.

One thing to check: the rheostat built into the headlight switch. This is activated by turning the switch knob. It's just possible your switch is adjusted for the dash lights to be all the way "dim", in other words, they will not come on, cause they are dimmed (IF that's the problem). Another item: fuses.

This pic was posted by somebody else in an older thread on testing to see if your gauges light up. While the cluster is removed you clip a postive wire (red) and a ground (black) to the circuit panel like shown and connect to your battery. This only tests light bulbs, not gauge function. Don't know if it helps you or not but here is the pic.