MY parking lights and side marker lights are not working, also my gauge lights are not working.
When I press the brakes, all my lights work, my headlights also work and my turn signals and hazard lights turn on, but my inside gauge lights, side marker lights, and parking lights are not on.
What could be the problem?
I have already checked my fuses and they are all still good.
And my bulbs are still good because how can they still work while I press the brakes, and use my signals and hazard lights.
Can somebody please tell me the problem before I take it to the shop?! Thanks!:confused:

Power to those lights come from headlight switch. Maybe headlight switch?

The mechanic says it's the "headlight module", could that be the problem, or check the headlight switch first, then another place said it might be the headlight relay, what are the difference?

If vehicle has both, remove easiest one first, Measure voltage on all pins(looking for 12 volts)Now, Get access to wire at parking light, and hook jumper between Parking lite wire and battery(fused would be safer.) Now look for voltage. Tone generator would help trace out.

The common headlight relay uses a momentary connection with ground, to mechanically latch a Relay(High Low High Low etc.)Low goes to low beam, and high goes to hi beam,
And indicator. Not thinking Headlight Relay. Do you have high and low beam?

Maybe head light switch, module, or unfound fuse.

If vehicle has both, remove easiest one first, Measure voltage on all pins(looking for 12 volts)Now, Get access to wire at parking light, and hook jumper between Parking lite wire and battery(fused would be safer.) Now look for voltage. Tone generator would help trace out.

The common headlight relay uses a momentary connection with ground, to mechanically latch a Relay(High Low High Low etc.)Low goes to low beam, and high goes to hi beam,
and indicator. Not thinking Headlight Relay. Do you have high and low beam?

Maybe head light switch, module, or unfound fuse.


I replaced the headlight switch with a brand new one yesterday, and the module there is none, Mercury started making them on 1995+ models, and all fuses all good.

The only thing I noticed is there is something that burnt on one of the connectors that connects the headlight switch, its like a light brown/white stripe wire, is it possible for a wire to not work if there is burn marks on the connector?

Apply voltage to wire of parking lite, then go to light brown/ white stripe wire and see if it has voltage. May need to put needle into wire, check for voltage, then at connector,on wire.
Loose connections generate heat, may have burned open at connector.