97 G Voy will not crank up

The problem comes and goes every month. The van just will not crank and i had to keep trying.. sometimes after a few hours it will start. all the wiring, starter and battery have been checked to be OK. Once it gets started, then it will run for a few weeks or even 2 months, then during rainy days the problem comes back. The mechanic at Pepboys could not find what the problem is. I hope no one has to go through the same problem, but if there's anyone out there who knows how to fix it, please let me know.

Thanks

Sounds like a starter relay (solonoid) is marginal.

If when cranking, all you hear is loud click, but no cranking of the starter, it is probably the starter relay is going (It's an intergral part of the starter so
just replace the starter).

When you turn the ignition key to start the car, the starter must first mechanically engage it's drive gear into the fly wheel. This is what the starter relay/solonoid does. If it does engages FULLY (the starter drive gear can be damaged/worn or the fly wheel can have a chipped tooth so sometimes they don't mesh gears proper ), then full battery power is sent by the starter relay to the starter motor.

It will not crank, the starter relay is engaged. If there's a worn starter drive gear, can it start for a period of time and then dies and then starts again after 1 day.

Yes, it can behave like that (intermitant). The problem can also be contacts in the starter relay can be worn. If the drive gear doesn't mesh, I used to move the crankshaft (i.e. flywheel to a new position) in the old days to get over a dead spot. Easy to do on older cars. In your case, rain may be shorting something out in the solonoid/relay.