My wife's '04 Tahoe Z-71 has occasionally had trouble starting, like the battery is low. Yesterday it wouldn't start at all, just clicking noise. I brought her to work and came back 6hours later. It was in garage, in park, no key in ignition, in off position and the lights would come on, it would try to crank (just dead battery clicking) then lights go off. Truck would repeat that process every few seconds. I put key in, turned it on then off again. That stopped the ghost cranking. I have no idea what's wrong. The battery is excellent, had it checked.
Any ideas???