Dennis I have been towing an HHR for almost 6 years I think. Instead of a fuse, the guy that installed my baseplate and wiring ran a charge line from the coach. It connects to the battery on the HHR and thus charges it (supposedly) as you are driving. The down side is I've had a couple of instances where the cable didn't make good contact and sure enough, I had a dead battery at the end of the day driving. But towing 4 wheels down has never been a problem.