gwhitten

My wife’s ’92 Grand Marquis has no rear turn signal and no brake lights. The brake light in the rear window does work. I have checked the fuses and they are fine. The backup lights work and the tail lights work when the headlights are turned on.

What should I look for that could cause this?

Thanks

gwhitten

Based on the wiring diagram and a similar post I have ordered the Multi Function switch (turn signal, dimmer, wiper/washer) and will replace it. I hope this solves the problem.

I found the wiring diagram at AutoZone.com under the repair guide section.

thefonz

Let us know if that fixes it. A repair manual for your car is also quite useful. Although many don't care for Haynes or Chilton's, they are better than no manual, and are only about $15.00-$20.00

gwhitten

The Multifunction switch did not solve the problem. I don't know what else to check. The parts store would not take the one back since I had connected the wires to it.

I guess I will need to take it to a dealer to see if they can solve the problem.

I do have a Haynes manual and the wiring diagram is the same as the one I located on the net.

Anyone who has a suggestion I would appreciate the information. I am already out $70 for the switch.

gwhitten

I brought out my multimeter that I bought last year but never used and I checked the wiring in the trunk and found I was getting current to the connector when the brakes and turn signals were applied. Removed the brake light assembly on both sides and then replaced the bulb with a new one and solved the problem. Looking at the bulb you would never know it was bad.

I have learned to never trust your eyes when checking bulbs, what I thought was good was not. I would never have thought both left and right bulbs would have gone out at the same time. They may have gone out at different times but when I saw they were not working they were both out. I have learned to test electrical circuits before replacing a component.

thefonz

I thought about asking if you checked the bulbs, but sometimes people on here get offended over a question like that.

Tom1222

My brother has the same problem with his 94 GM. The dealer told him it is the "safety neutral switch" which controls the Brake lights and the Brake interloc system which prevents you switching into Drive from Park.
He had to first switch the car into Neutral then start the car and them put it into drive. That switch fixed his problem

mickey

It also happend to my GMC turn signal...try the resistor...

the resistor will get just as hot as a bulb will since that's what your doing is making the circuit think that it has a regular bulb

tbird100636

That would be the back-up lights, not the brake lights, and the neutral switch prevents starting the vehicle in positions oither than park or neutral. The brake/shift interlock prevents the vehicle from being shifted out of Park without the brake pedal depressed. It gets output from the brake light switch.

__________________
Master ASE Certified L1 Chrysler Technician- still a Ford fan at heart.
1964 Thunderbird Hardtop- Chantily Beige- 390 FE 4V V8-Uncle's Car
1966 Thunderbird Convertible- Red- 390 FE 4V V8- Uncle's other car- waiting for paint and body work!!!
1967 Mustang Convertible- Blue- 289 V8- helping a friend re-assemble this classic