NO REAR LIGHTS

1985 Mercury Marquis

Tiny

Franz

January, 14, 2011 AT 4:43 PM

I have a 1985 Mercury Grand Marquis and my brake and tail lights are not working. The directional lights only work sometimes.
When I step on the brake, the dash and the license plate lights come on. Any idea what may be the problem?

FOUND 576 RELATED QUESTIONS

Panel Lights Dont Work

10 ANSWERS
2 IMAGES

Glowing Lights

10 ANSWERS
3 IMAGES

3 Answers

Tiny

JDL

January, 14, 2011 AT 5:59 PM

Older wiring diagrams are hard for me to read. In the diagram, the brown wire is voltage for tail lamps, the black wire is ground, the other wire is voltage for brake and turn. Brake and turn use same bulb filament, just not at the same time, they are wired through the turn signal switch. Did you check all applicable fuses, bulbs and bulb sockets. I'd have to check those wiring circuits to find out what is going on.

Tiny

Franz

January, 14, 2011 AT 6:27 PM

I have checked bulbs and fuses and both are good. I have not checked the all the sockets at this time.

I was wondering, could this problem be either the headlight switch or the brake light switch?

Tiny

JDL

January, 14, 2011 AT 6:52 PM

Any fuse you check, you need to check for voltage also, use a voltmeter. Even if the fuse is good, if no voltage, the circuit is dead. Some fuse circuits are hot all the time, some go hot when you turn on the key. The voltage to your brake switch is usually hot all the time, check for voltage. The switch should be activated by the brake pedal arm.

Please login or register to post a reply.

Blend Door Actuator Replacement
Cabin Air Filter Replacement Honda Civic
Open Hood Video
Cabin Air Filter Replacement Chevrolet Tahoe
Window Switch Replacement and Test
Instrument Cluster Replacement GMC Yukon