My 1987 240DL flunked VA safety inspection for "no brake lights". Last time I looked at my wife driving away they worked fine. Not now though! I've found power to the brake light switch and away from it when the pedal is depressed. I've studied the wiring diagram but can't figure out the path to the rear lights. (the tail lights work fine) The wire from the switch to the lights (blue with red tracer)goes to some device after which different colors wires go to the lights (blue ?). I think the "burned out bulb" warning sensor is that device, but I can't figure out where it is or looks like. I also discovered that the back-up lights are not working. All thoughts and suggestions appreciated.

Dear Barry S.
Before spending money on relays do the following: Depress the brake pedal with a stick and wedge it between the front seat to hold it in place, put the shift lever in reverse, put the key in position II (On) and test for power at the connection at the rear light panel. If no power check for corroded/loose ground connection at the panel, and check all appropriate fuses. If you have power check the printed circuit board. They are notorious for wearing out where the incoming power connector attaches and also where the bulb holder connectors press against the circuit. Every Volvo I have ever owned has had finiky tail lights but I have never heard of the bulb failure warning relay being the cause of lighting failure. In fact the bulb failure warning relay is usually accused of being too sensitive and warning of failure when there is none.

Good luck
Len K

For the 240, my wiring diagram shows the R stop to be Yellow and L stop Yellow/Grey. The backup lights are on a black wire.

Since all these problems seem to have happened together, I'd suggest checking the connections back at the rear. Each taillight combination has a flexible printed circuit board. The sockets fasten to these "boards" and the power comes in through connectors which go to the copper circuits on the boards. This copper can corrode and make poor connections. Also I've had the wire connectors make poor contact at the boards. You should start where the wires come in from the front of the car and clean and tighten that connector first. If it was loose, it could affect both stop lights and the backup lights. Check the voltage back at these wires at the connector to be sure there is no break forward of the connector.

After I posted my original message, I located the bulb failure relay. I checked power between the BL/R input and the 2 Y outputs, L and R. Nothing! When I jumpered between the BL/R wire and each of the Y's, in turn, I got stop lite illumination. I think this means the relay is bad. $130 from Volvo and $70 from Small Car Parts. I can get it Monday PM from Small Car Parts. Is my logic sound? If this works, I"ll proceed to the back-up lites which do not seem to go thru this relay.

It may be too simple of a solution but I would start with the fuses. The contacts become oxidized so just a little cleaning can fix many electrical issues on my Volvos. Hope this helps.