PeachParts Mercedes-Benz Forum - View Single Post - No headlights, rear lights, or high beams (w124 300d)

Maxbumpo · #5 08-20-2015, 10:32 AM

Well, a wiring diagram would be really useful, but maybe hard to find for a euro car.

I like leathermang's idea, you'll need to go through the entire system.

Pull all the fuses out, and also check at the relay that controls the "light out" indicator. All the exterior lights go through that relay, and it compares the current draw of the left side of the car to the right side, and lights up the dash bulb if there is an imbalance. You can test each side of each circuit for a short to ground after you remove the bulbs (which provide a path to ground), if you know what pin at that relay socket goes to which light bulb. Again, wiring diagram... You may have some luck just looking at the wiring colors and stripes at each bulb holder, and checking that against the wires on the bottom of that relay socket.