Hi Folks, I have a 95 Dodge 3/4 ton diesel pickup regular cab long bed with automatic transmission and no mods. For some time now, it has intermittently refused to crank. It'll be fine one day and the next day it won't.
When it won't crank, it seems that all the other things controlled by the ignition key work normally. For example, the indicator lights are on, the air heater works, etc.
One time only, it did not crank right away, but did so after I held the key in the start position a little longer.
Jiggling the key, the shift lever, wiring harness, etc., don't have any effect.
Today, I tried removing the starter relay and jumping the sockets while the key was in the run position. Nothing happened.
I then tried a wire from the + terminal of the battery to the relay sockets. Again nothing happened.
Finally I went underneath and jumped the starter with a screwdriver. It started the engine.
I let it run and warm up for 15 minutes. I shut it off, and it restarts with the key.

Does all this point to something in particular as the most likely culprit?
Thanks for your thoughts.

 

I would keep a jumper wire attached to the small terminal on the starter, have a voltmeter or test light attached to it & the other to ground, every time you turn the key to crank it should have voltage to the small terminal, if you have voltage everytime, then the starter needs work. If not, you need to investigate the ignition switch or wiring.

 

Bad starter- replace or rebuild

 

Not necessarily - it could be a problem with the trigger wire to the starter. The fact that the OP (original poster) is able to jump it from the starter's battery terminal to the trigger terminal indicates that the starter does work - at least sometimes. The OP needs to test the trigger wire, especially with a wiggle test.

 

I had a similar on-again/off-again starter problem in my '95. Turned out to be 2 problems. (1) The old car alarm that I hadn't activated in over 15 years had self-activated somehow, and it took me a day to figure it out, and trace down the ignition wire that whoever installed the alarm had cut and routed to the alarm. Once the ends of that ignition wire were re-soldered together the truck still had occasional problems starting. I got the Denso starter rebuilt and that solved all problems.