My 15A fuse under the dash that controls the backup lights and the A/C blows every time I shift from Park to Reverse. Any ideas on how to fix? I do notice a sticky residue on the rubber gasket where the gear shifter goes into the steering column. I hope that my wife didn't spray cleaner down there when she cleaned my truck.

Thanks in advance.

 

There is nothing in the column to cause this, the switch is on the transmission where the shift cable goes. I would start checking the tail lamps and connectors. It COULD be a bulb, though the filament usually fails and there isn't enough current there to blow a fuse, but if the two leads in the bulb made contact, it's a possibility.