Hello all. My 1989 240 Wagon's breaklights have stopped working (all three including the one in the back window) and I need some advice. All other lights on the car work (turn signals, back up, running.) I have replaced the fuses and bulbs to no avail. Someone suggested that many times this is the result of the switch under the break pedal or possibly a relay in the dash? Any ideas? Thanks so much to anyone who may have fixed this before or has any insight.

 

As far as I'm aware there is no relay for the brake lights. The switch is mounted on the brake pedal bracket and can be adjusted. Check to see if you have 12v going in and out at the switch with either a meter or a test lamp.

 

If you don't have a meter or a test light, just short the two wires going into the switch. If the brake lights come on, the switch is either maladjusted or no-good.

 

Hi...some troubleshooting ideas. I have an 86 240 and had the same problem, but my brake swithch was OK. The problem turned out to be the sensor unit for the bulb failure warning light system, which is found just under the dash left of the steering wheel. It is a larger round red cylinder with many wires out one end. Apparently these sensors have/had a weak diode in the brake light circuit. In a previous post, I related info given to me about installing a jumper to bypass the brake light only portion. I also had a good look at the rear taillight metal circuit board and connections. Cheers and good luck.