Thank you for reading. Question is on a 1972 280se. Car was running fine. I stopped at a shop went in, came out 15mins later car would not start.
Issue is that everything electrical seems to work fine, except for the radio which worked before. I turn the key and I get a single click under the hood and hear the fuel pump whirring.
Any ideas? The other side of this is this: I notice that there are 3 wires on the starter, one is disconnected (corroded through). If I reconnect this same wire to its original point, I still get nothing. Thought I had figured it out when I found this wire, but guess not. Can someone tell me if there are 3 wires on the W108 that need to be connected or is it just the two and if so what are they for. Thanks again!

Yes, there are three wires on the starter, not including the battery cable.

One goes to terminal 50, one goes to terminal 30 (battery cable) and the other goes to terminal 16.

The wire to terminal 30 (battery cable) powers all the accessories and ignition switch -- if the radio doesn't work, this is probably the wire that is off, and the starter won't work since there is no voltage being applied to the solenoid when you turn the key. Probably red, but not marked on my diagram.

Terminal 16 goes to the ignition and bypasses the resistor to give hotter spark when cranking.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

There are myriad possibilities. I'd start with the battery. A battery can still run a radio or fan, but not be able to crank the starter. I think the cars only came with automatic that year, so the neutral safety switch on the tranny could have gone south. This switch only lets the car start in park and neutral. Sometimes you can get another start or two out of the starter by rapping it a few times with a hammer. If that works, it's time for a new starter.

Good luck,
Peter

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