2014 F70 4-stroke intermittently loosing electrical power

[Frank-NC]

I was cruising down the lake at full throttle and suddenly the motor lost all electrical power. The tilt/trim wouldn't work either. This is on a Carolina skiff with a 2014 Yamaha F70 4-stroke. The gages worked, and showed I had 13v on the battery. I took the cowling off and checked the fuses and wires to the starter/ect.; Nothing was loose. Tried the ignition and it worked. Shut it off, put the cowling back on and it was dead again. I repeated this process several times and made up new dictionary curse words. Finally was so dumbfounded with it that we drove back to the ramp with the cowling off. Then, to add insult to injury, when I had it back on the trailer I put the cowling on and tried the trim/tilt and it worked just fine. Ran it with earmuffs back in my driveway both with the cowling and without, poking around and wiggling every visible wire and connection but I couldn't reproduce the problem!
Any ideas on what to focus my investigation on? Many thanks in advance!

[rodbolt17]

when this happens does the pan trim switch work?

[panasonic]

Look on the inside of cowl closely and see if there are any rub marks or shiny spots where something maybe chafing.

[Frank-NC]

I'm not sure what the "pan trim" switch is but the trim switch on the throttle handle is the one we were using to see if the motor had power when I was troubleshooting on the water. When the trim worked, it sound crank/start. If the trim was dead, the motor was dead.

[walleye1]

The pan trim sw is on the lower cowling on the engine.

[99yam40]

Are there gauges on this set up to tell you if it is overheating or other problems when this happens and what the problem is?
Does this setup have an alarm for problems like over heat ?
and does it function as it should?

[Frank-NC]

Thanks for all the replies. The pan trim switch was dead like the one on the console and I didn't have any alarms, temp was fine. I think I just found the problem, although I won't know for sure until it happens again! I was wiggling wires again and I noticed the main ground cable that mounts near the starter was a little loose. I wiggled it while using the trim switch and it actually sparked. So I cranked it back down. It must have been loose enough to not pass enough voltage, and the wire runs near the cowling so it probably moved into the perfect spot to lose contact. I'm hoping that's the end to this story. Thanks