transfer case and electrical short
97 NAS 90 with auto box. Fuse #17 (engine immobiliser, brake lights, turn signals) started blowing once in a while and got to a point where it blew as soon as I turned on the key. Ended up melting a gray wire with a black stripe I traced to the transfer case. I think it is connecter C683 going into the gearbox interlock unit?? When this is disconnected the fuse does not blow. It is not the low range light switch. Ideas on what failed? Is this a simple remove and replace with a new interlock unit (if that's the problem)? Thanks in advance.