So my brother decides to pull the the cig lighter plug out of the truck and hook to the spare battery. Well he hooked it up reverse polarity. Error light came on and now nothing. Checked fuse in the cig. lighter, on the 120 volt plug, and the internal fuse on the what looks like internal inverter. The frig. will run in the emergency on, 120 volt mode. No lights on the control panel, power, temp, turbo, nothing. Any ideas?