Would check if the generator is hooked up to the house battery or the truck battery, sounds like it is the house battery though which can cause problems when you dry camp and run the house battery down and have to boost it enought to get the gen to start. Ours is off the truck, so even when the house is down to below 12v it will still start. The wifes mothers rv though is off the house battery, and the last camping trip we where on had to bring the jumper cables out to get the gen to start.. Our gen in a 1977 motorhome BTW only shows 90 hours of run time...