To tow the Enclave behind a motor home the instructions say to puu th 50 amp batt1 fuse. I went to three dealers to get a spare in case I lose one. None had the fuse or know what it's called (so I can buy elsewhere). Does anyone know what these fuses are called (nomenclature such as AGC, mini etc) or where to buy them. The dealers don't have them and must order from GM.