I am getting an Intermittent no start on 85 300D evry two weeks and my battery/alternator are okay...as i recall from my 240D, the starter motor is going bad.

My questions are:

(1)Can I just replace the solenoid?

(2)and what's the trick to use a jumper wire to start until I get this fixed. I kind of remember that when i got in a tight spot and couldnt start, i could use a jumper from (where?) to (where?) to spin the starter motor. It was a temporary fix, not a permanent, one..