Pulled the cover and it was fairly dusty but not to bad, vacucmed it out the best I could. Did find a stick in there about 6" long like a popsicle stick, don't know where it came from and got it out. Looked for the fan and cooling fins but didn't see them(?) All vents were clear. Did find a very small button on the back of the battery box on the circuit breaker, didn't see before as It was covered by foil insulation. I haven't plugged it back into shore power as I really didn't do anything that I feel will fix the problem. Where would the fan be?