Question:
Im having trouble with the tail lights and brake lights my 2006 volvo 780 . The back signal lights work but neither brake lights or tail lights work. I checked the fuses and they are all good. Any suggestions
asked by: Jaime
Expert Reply:
It looks like the Volvo 780 stopped being produced in the early 1990s and was replaced by the C70. So it would appear that if you have a 2006 model year that is like the 780 it would be a C70.
At any rate, the vehicle should have separate brake lights from the turn signals so basically every function would be on a separate circuit. The first thing you can check would be the bulbs (if it uses regular bulbs) and the bulb sockets to determine if there is corrosion or a burned out bulb or both.
With new bulbs and clean sockets, you can use some dielectric grease, # LT37534, to repel moisture and prevent corrosion. Some vehicles use fuses and relays to control certain functions so check the owners manual to see if there are any relays associated with the lights.
If the wiring system on your Volvo is a multiplex or PWM (pulse width modulation) system then it is also possible that the part of the computer or body control module that controls the lights needs to be inspected, repaired, or replaced. A dealership would have to take care of that because it could be a fairly involved repair.
Loctite Bulb, Lamp, and Electrical Connection Dielectric Grease - 0.33-Oz Tube
