Head Light

If the switch was defective, you wouldn't have any head lights. Does the high beam work?

There are two separate fuses, one for each side. Check them under the hood. I seem to recall they are 20 amp fuses. If they are good, use a test light to check for voltage on the common terminal in the head lamp socket. If you have voltage there, test for continuity to ground on the other two terminals.

Caradiodoc

Hold on. If the high beam works, you have voltage to the common terminal. The fuse must be good. I should stop here and ask, do you have one headlight bulb on each side or do you have "quad head lamps"?

To help me plan the troubleshooting steps, can you access the wires in the bulb socket from the backside without removing the bulb? I don't approve of piercing wire insulation to take measurements. Let me know if you can poke a voltmeter probe through a rubber seal in the back of the socket.

Next, I only have a 1999 service manual. If you have a violet feed wire, a red / orange, and a violet / white, the circuits should be the same as yours.

There really isn't much else in the circuit. The violet / white wire goes through a joint connector, (in the fuse box), to the low beam wire from the right head light which is working. Either that wire is broken, or more likely, the the terminal in the socket is corroded or stretched out.

Caradiodoc