All right folks, I have a good one. After 405K miles, my 1985 300D decided that it was not going to start the other day. I pulled into the garage, shut the car off and realized that I was not all the way in, and tried to restart. Nothing:-(

Thinking starter or solenoid, I checked wiring, stumbled across a badley corroded #12 wire at the battery post, repaired it, still no start. When I turn the key to just before start, everything dims in the car, the dash lites, etc. When I go all the way to start, I hear straining.

Checked wiring, fuses, and stumbled across the glow plug relay. I found that if I unplug the glow plug cabling from the relay, everything seems to work fine. The starter even works.

Now, why when I remove one wire at a time from the glow plugs did I not find the problem. Only if ALL wires are off the glow plugs does the starter turn. How do you check the glow plugs! Is this my problem??