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markeb01 · 10-28-2009, 12:05 PM

The way these dome lights work is by controlling the ground. Only one of the wires going to the light should have power, and is normally hot all the time. The other wire goes to the rheostat connector on the frame of the headlight switch. Twisting the knob/shaft varies the amount of ground through the rheostat, until it reaches the end of the cycle which provides full ground and full bulb brightness. It took me a while to figure out. I had to read up on it since I'd never seen anything wired in reverse like this. Normally the switch always controls the hot side.

10-28-2009, 12:05 PM	#2
markeb01 Senior Enthusiast Join Date: Feb 2007 Location: Spokane Valley, WA Posts: 8,356	Re: dome light problem The way these dome lights work is by controlling the ground. Only one of the wires going to the light should have power, and is normally hot all the time. The other wire goes to the rheostat connector on the frame of the headlight switch. Twisting the knob/shaft varies the amount of ground through the rheostat, until it reaches the end of the cycle which provides full ground and full bulb brightness. It took me a while to figure out. I had to read up on it since I'd never seen anything wired in reverse like this. Normally the switch always controls the hot side.