74 duster elelctrial help

You need to send me a PM, that is, "conversation." I have a digi copy of the 74 manual which is unique, as the electrical has CHANGED from 73. There is no free download of a 74 manual

You mail me a prepaid mailer with a thumb drive, and a return addressed/ paid return mailer, and I'll copy the files and send it back

There should be no fuse in the RED ammeter wire. If so, the fuse link has blown at some point, and someone has replaced it with a fuse, which is likely not heavy enough under some charging conditions, AKA heavy load and battery that is partly discharged

As far as the ammeter bypass, it's not quite that simple BECAUSE the existing wiring STILL must be in decent shape as it stil acts to supply power, through the bulkhead, into the passenger compartment. You must make certain that the bulkhead terminals for the big RED ammeter wire, the big BLACK alternator output wire are in good shape, and that either the ammeter terminals are in good shape, or that you splice the red and black ammeter wires together

You want to use a good big wire for the bypass with either a fuse / fuse link or breaker. This depends on the size of wire and the size of the alternator.