1982 Mercedes Benz 300sd Merc-Benz 300sd - ignition relay p

ARAEFEL429

MEMBER
1982 MERCEDES BENZ 300SD

Electrical problem
1982 Mercedes Benz 300sd Two Wheel Drive Automatic 270000 miles

I recently changed the glowplugs and starter on my 300sd - when I attempted to start the car, the engine was silent. I tested the voltage across the starter when the ignition was turned on - 0 volts. I hotwired the car manually and it started without an issue with the new parts. I think this indicates a ignition relay or switch problem? Is there something to replace that is simple and doesn't require 'special' tools that a non mechanic would have? Is it located in the steering column or someplace else? Also - do you guys know where I could find a wiring diagram for a 1982 300 sd?

1 Reply

DR LOOT

MECHANIC
2,311 POSTS

The only problem I find with your question is, you did not tell me if the car started before the starter failed? If that's the case, you probably did not get all the wires hooked up property on the starter, so check the starter and make sure all the wires are hooked up in the right position. The on demand manuals I have access to online, do not have any electrical information on the car, but I do have some old factory manuals that I will scan for you if you still need them, let me know.