Another Ammeter bypass question:

To get back to the weaknesses in the system... IMHO one of the big problems that leads to problems in the installation of a high amp alternator feeding new electronic equipment that create loads that were never there stock. The original alternator in a 70 Dart was (I think) 34 amps. If you had AC then a "heavy duty" 45 amp unit was used. Chrysler recognized the issue with the weak connection at the bulkhead when they built fleet vehicles like taxi cabs and police cars and put a grommet in the firewall and routed the main power wires there when they used those "really big" 56 amp alternators for cars that did lots of idling and had lots of extra equipment added - 2 way radios, sirens and lights, fare meters, etc. Now go check what the amperage on a new alternator is... 60, 80 100 amps is common. If you wire the add ons with separate fused sources from a battery source not under the dash, life is good.

I wanted a chrome alternator on my show car, found a round back and installed it. When I slowly fried the under dash wiring harness and bulkhead connector, I had the alternator tested - 105 amps! After research here I went looking for a 45 amp alternator, but to get one I had to take an old one to a rebuild shop.