My 1984 300 six has been going through starter solenoids like pez. I have a new battery, new battery cables, fairly new and fully functioning starter and a new starter solenoid that was the best that I could find. It will start fine for days, weeks or months, then it just clicks the solenoid out of the blue. In the past rapidly repeated twists of the key will start it, or tapping the solenoid, or connecting the battery and starter terminals on the solenoid. Most recently with all the new parts, suddenly it acted like the battery was dead, drew down all the lights and wouldn't even click the starter. The 3 week old battery was down a little bit, but even after a full charge it wouldn't do more than click the solenoid. Jumped the solenoid terminals and it started right up. Started a few more times fine, then went back to just clicking. Several attempts finally got it to start. What could be causing my truck to eat solenoids?

 

I doubt the solenoids were bad to begin with. Remove and clean up ALL connections associated with the cranking system of your truck.That includes grounds, especially the one which attaches to the engine block. Any questionable cables need to be replaced. Do that and then let us know if the problem continues.

 

Turned out the positive cable was bad. Thanks!