Hi Kent et al.,
I have a 1982 240D with manual transmission. Lately I've been having intermittent starter trouble. I've followed the 'Why Wont My Mercedes Engine Crank Over' guide.
My battery is in good condition and reads 12.4VDC, and I'm confident the charging system is working correctly.
When I jumper the solenoid I get the same behavior as turning the key. Here's what happens:
The solenoid seems to be working properly, and sends current to the starter. The starter spins, but fails to fully engage. I hear a rattling/grinding sound, which sounds like the gears failing to mesh, and instead chattering against each other.
If I connect the positive and negative terminals of the solenoid directly to the battery, it works perfectly when I turn the key. So, I suspect my failure is related to a poor electrical connection. In other words, the starter isn't getting enough juice to fully engage and turn over the engine.
I have an audio recording of the noise available if that would help.
What can I do to correct this? Should I replace the cables which connect the starter? Any input would be appreciated.
Thanks!