How do I determine which of these solenoids is the problem?

[billy6fitzgerald]

Thinking I had narrowed down my starting problem down to two solenoids, I moved a big bundle of wires out of the way and I now count 5 of these solenoids. Holy cow! I have stuck the test light on each one of them while the key is in the on position and also while someone is trying to crank it. All of them have three posts - two big ones and one small one. One of the big posts is hot on all five of them, even without trying to crank it. On the four solenoids that are back to back, I can't get the test light to come on at all on either of their two remaining posts whether the key is in the "on" position or in the cranking position. On the fifth solenoid, the other large post will light up with the key in the cranking position and the small post will also light up with the key in the cranking position. That fifth solenoid is the one making the "click" sound when the key is in the cranking mode. All of the others are silent. Is there a way to figure out which one is bad or if they are even the problem? I included photos of them.

 

[billy6fitzgerald]

Re: How do I determine which of these solenoids is the problem?

The solenoid in the second photo (lets call it #5 solenoid) has the starter wire on it, yellow with a red stripe. So, I hooked up jumper cables from my running truck to the boat battery just to make sure that's not the issue. Then I touched a screwdriver across the two big posts on solenoid 5 and got tiny little sparks and the engine did not try to crank. Thought I would've gotten bigger sparks, the kind that make you jump even when you're expecting them. I went ahead and touched the screwdriver across the big posts of a couple other solenoids and got the same little sparks.

Does this mean anything? Have I found a bad solenoid or are the solenoids not the problem?

 

[billy6fitzgerald]

Re: How do I determine which of these solenoids is the problem?

Ok, one more additional attempt tonight after talking to the guys at the boat store. They suggested that I hook up a jumper cable from the positive battery post and touch it to the hot post of the slave solenoid and see if that bypasses a possible problem between the ignition and the solenoid. It didn't do anything, no sparks, no engine turnover, no solenoid click. Then I touched that same jumper cable to the other big post and only got little sparks. No engine turnover, no starter turnover, no clicking. Additionally, on the solenoid that is on the starter, I touched the big post of the cable that goes into the starter. Only got little sparks, nothing else.

I'm at a loss here and can't think of any other combinations. Any ideas? Does this prove that something specific is faulty?