Please help diagnose my starting problem

[nwbabybronco]

My truck suddenly decided not to start the other day while we were out wheeling. It had been running great with no problems, then I parked to watch a buddy try to get stuck, and it wouldn't start up again. We managed to roll start it, and it seemed to be running fine again, but I stalled it getting over a rock on my way out. It hasn't run since, despite numerous attempts at roll starting, jumper cables, etc.

1988 Bronco II, 2.9L, 5spd

Wouldn't start even after swapping in fresh battery (which it promptly drained). The solenoid would make one click and then it would die, so we replaced it. The new one makes at least one click and occasionally a whining sound (point is, more happens).

The test light shows full power getting to the solenoid, but flickering at best on the output while cranking. The same flickering can be found where that cable meets the starter.

I tapped the starter with a hammer and attempted to roll start again, so I don't think it should be jammed or something.

Grabbing the PS belt I can turn the pump, alternator, and main drive pulley. This means the engine can turn over, right?

Where do I go from here? Thanks for the help!

 

[nwbabybronco]

So I'm thinking the starter might be the problem. Does it make sense that it somehow could have been damaged or contaminated by running through deep, muddy water?

And what of the second battery dying so quickly? It seems like there is more life-suck than there should be. Might a short somewhere be the problem instead?

Any ideas? Thanks!

 

[nitro71]

I'd start with cleaning your batter terminals and cable really well. Getting any black corrosion off them. Then spray some permatex anticorrosion(purple) spray on them. While your doing that have your battery tested at a parts store. I like Duralast(Johnson Controls) batteries myself.

Then I'd look at the cables. If they look good I'd probably swap the starter out. Not sure if you can bench test the starters.

That's probably how I'd start out.

 

[nwbabybronco]

It was the battery terminal contacts. A bit embarrassing, but it's up and running again.