I have a 2004 Hummer H2 and it doesn't crank when i try to start it. The battery is good...i messed around with locking and unlocking the doors for a bit and it eventually started up again it was fine for about a week and now its happened again.... it works perfectly when i take it to the mechanic and they don't know what the problem is... has anyone come across this issue. I would appreciate the help..