I can't imagine a circuit much simpler than the headlights. Check for voltage from the headlight switch to the dimmer, then check dimmer output to the high and low beam wires. If you've got voltage to the light sockets, replace the bulbs. I assume the harness wires are color-coded? A simple multimeter, or even a test light should be all that's required to check those circuits, assuming you can read color codes. The voltage from the switch will go to one terminal on the dimmer, and switch on and off as you operate the light switch. From there, there's only two wires, one for hi beam, one for low, so the circuit has to split somewhere to go to each headlight. Just follow the wires, checking for voltage anytime there's a connector or junction block.
Jerry

Edit: Be sure the headlight bulbs are grounded, or nothing will work.
Jerry


Last edited by Hotrod Lincoln; 10/08/2010 1:59 PM.
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