i will bet that you blew that fuse for the radio. many times i have seen that happen. any power out let that you put into a car to either charge your sell phone or give you directions usually takes more current than the system is set up to handle. i had the same thing happen to my grand father in his truck. i wired a second power out let just for that purpose. with mine i went directly back to the battery so that nothing else was effected, and yes there still is a fuse in that circuit.
how to test the fuse is simple, look in the fuse box for the radio fuse. pull it out and look in the middle of that fuse. yours should be blown given the situation.a good fuse will have a thin wire that will bridge between the two posts for that fuse. you should be able to locate a couple of spares. try to match the fuse exactly, and look into a different power source for the gps.
how to test the fuse is simple, look in the fuse box for the radio fuse. pull it out and look in the middle of that fuse. yours should be blown given the situation.a good fuse will have a thin wire that will bridge between the two posts for that fuse. you should be able to locate a couple of spares. try to match the fuse exactly, and look into a different power source for the gps.