New starter, works intermittently, won't crank when hot

[MCAHunter]

Troubleshooting when 2002 response won't start. Couple times boat wouldn't crank when hot. No click. No crank. Decided starter or solenoid was probably going out so replaced whole starter unit (with new solenoid).  On install, get happy cranking, happy boat starting. After a few minutes idling and a few more starts, back to no click, no crank. 

Next morning, cranks and fires right up. Follows same pattern.  Starts fine a few times, then nothing. No click, no crank. Thinking I got a defective part, I pull out trusty voltmeter which says differently. 12.5v at power line to starter, but 0 at ignition wire to starter even when turning key.

Ideas? I've got a mefi 4 scan tool but not sure which sensor to look for as possible interference with ignition. To my knowledge, it should be just the neutral switch and red safety switch between the key and the starter, right? Key is working because dash gauges light up and show appropriate levels and i get the pre crank beeping i should get. 

[tvano]

starter relay?

there are three relays very close to the ecm.  ign, starter and fuel pump.  the relays are alike.  swap them around and see if your intermittent issue moves.

while moving relays around take a close look at the sockets that they fit into.

[wdr]

I am betting the solenoid is bad. Had the same issue on my ‘10. Cold it would it crank it over, albeit hesitantly and when it got heat soaked nothing.

[MCAHunter]

SOLVED!

Thanks for the advice, while I was checking those things I happened to bump the wires to the neutral switch/sensor on the transmission and one of the lines was apparently almost disconnected because that bump finished it off.  Temporarily, took the two wires and twisted them together and sure enough it fires right up.  

I doubted it would be the solenoid since I'd just replaced that and the starter (yesterday), but I have gotten defective parts before (which really sucks for troubleshooting).

Anyway posting solution for the good of the herd for other's troubleshooting benefit.  Frustrating to know now since I already bought a $220 starter and paddled home, now realizing a piece of electrical tape would have had me up and running.  Anyway I'll run a few test to confirm that was it then grab a new wire connector at the store and get the switch back in place.

Again--for other's having this problem, at least my method was to test voltage at starter power cable (the big one that goes right to the battery), test grounding of motor by testing voltage first against battery and then against motor block.  Both reading same voltage usually means grounding is good.  Then tested voltage of wires behind ignition switch to make sure one goes to +12v on key turn (it did), then doing the same to both sides of lan safety switch (it did), then testing voltage to the ignition wire at the starter (which never changed - stayed at 0 no matter key position).  So then I knew it was a wire loose or a sensor/switch in the ignition switch line somewhere.  Lucky fortune that I happened to bump neutral switch wires because I'd have spent another couple hours otherwise checking the relays.

Thanks again!  Off for a little wake surfing.