Initial experimentation with external shunt ammeter
Talk to me like I'm the electrical dipshit I am and tell me what's the advantage here? I know there is one, or else you wouldn't be posting about it.
Simple rusty. All the OEM cars, GM, Ford, or Mopar, that used "external shunt" ammeters, used the car's wiring for the shunt. The small wires feeding the dash instrument were tapped into the harness. So the full current of the vehicle loads, AND the charging current which goes through these cars normally, and back and forth through the bulkhead, is simply not there. In other words, the ONLY heavy loads going through the bulkhead are now just the operating loads, the headlights, heater, igntiion, etc, so with no charging current, amperage going "only" INTO the passenger compartment is greatly reduced
So no danger to an ammeter, and REDUCED danger to bulkhead connector
So far as a shunt burning up, that would be fairly "safe." And again, by using the car's own wiring as a shunt, there is nothing specific, really TO burn up other than wiring shorts that can happen anyhow.
What I hope to do, then with the 74 Scamp is:
1:.. Without tearing up the car, determine that WITH an ammeter bypass done, how easy or difficult it would be to find and perform proper harness points to splice the low current instrument into the wiring so that it operates properly
2...If that proves somewhat impractical, then use an actual external shunt in the engine bay, which would eliminate the ammeter / bulkhead problem
3...Then with that done the new instrument could be installed into an existing cluster similar to how guys are doing the voltmeter conversions
One thing I hope to avoid is the "Ford numbness." I've seen some Ford pickups owned by others, and my older Rangers, 86/87, you could turn the headlights on at rest and you had to "stare intently" at the ammeter to see if it MOVED. So I hope to avoid this situation, and come up with a truly useful reading
