Bulkhead Instrument panel bypass.

Another issue with the actual ammeter itself.......and this depends on the model year........is the construction of the ammeter and WHERE IT MOUNTS. If you read the MAD article notice, there is a photo of a melted ammeter. I'm well acquainted with that mental picture, having see a few pickup ammeters that looked exactly like that .......from winches, "big" off road lamps, or snow plow hoists

In some years, the ammeter is mounted--------always by the studs------through the wall of the cluster casting WHICH CAN BE PLASTIC. If heat from current causes anything to be "loose" then the heat gets worse, the "loose" gets worse and a great big snowball effect (fireball effect?) happens.

Also, on some ammeters, THE STUDS ARE NOT FASTENED really, and act sort of like "bolts". So any looseness in the assembly, allows a loose connection between the stud(s) and the meter shunt---the guts of the meter. Another self destruct situation.

Now I LIKE ammeters, but the only way they can really be implemented in large current installations is WITH AN EXTERNAL SHUNT. This allows shorter, larger wiring, with good, solid terminations, and NO spade/ flag/ push on terminals such as in the bulkhead connector.