Need some help. The other night I was driving with an inverter plugged into the power outlet. Suddenly all power to the outlet stopped and the inverter turned off and wouldn't come back on. I plugged the inverter into the cigarette lighter and it worked. We've checked all fuses both visually and with a voltimeter but none are blown. Does anyone know what besides a blown fuse could cause the power outlet to stop working? Any info will be highly appreciated.