Im thinking one or maybe both of the start solenoids are bad, I found the battery draining short, but now today I went to start the truck, and just a click. Got good voltage in the batteries, and at the starter, and just replaced the small hot wire to the starter. How can I tell which solenoid is bad? I put a screwdriver across the two large terminals on the upper solenoid but it doesn't even click, and it seems like a lazy spark. But when I try it from the key, I hear a click/clunk but can't tell where it from.

 

if the solenoid doesn't operate with those terminals shorted out, I'd just go buy another solenoid...cheap part and easy to replace.....hth

 

I'm gonna get one tomorrow, but I just don't know if it might be the one the starter.

 

That's a relay on the fender. If jumpering the big terminals with a screwdriver does not activate the solenoid (the one on the starter), then the relay is NOT a likely suspect (jumpering basically takes it out of the picture). Have you load tested the batteries, independent of one another? Have you also confirmed that the engine is not locked up?

Both the relay and the solenoid can be tested with a multimeter, which is cheaper than either part.

 

The engine is not locked up, two brand new deka 850 cca batteries. It's just weird cause, right after my initial post, it fired right up. And also, when I was jumpering the relay earlier, like twice, it did engage the starter, but the other 30 times it didn't.

 

So it's either the main battery/starter wires, or main grounds, or bad connections on those wires, or the starter. Were the battery terminals on the main wires in good shape when you replaced the batteries?