Very odd problem

[fatboy11]

My wife's 2008 gas Club Car Precedent has a problem that I have no idea where to even start. It starts, stops and runs great on flat ground and going downhill. It runs great going uphill BUT if she stops at the top of the hill it will not start. I mean like ALL of the electrical is dead, no crank, no clicking, no nothing. If she doesn't stop it continues to run fine with no issues. When it does this we can let it sit for 3-5 minutes it starts right back up fine and has no issue again until another hill comes along. When it first started I would shake the wires on the microswitch thinking this was the issue because the wires did seem a little loose. It would seem to work BUT this was also after it set for a few minutes. I put new ends on the wires and replaced the microswitches but I still have the issue. It's got a new solenoid on it also. The starter was replaced last year. This issue started about 2 months ago.

Does anyone out there have any idea at all what I can look for?