As Jerry says, you can see by looking at a 55.1 "ammeter", it is kind of mis-named. It's a Discharge/Charge indicator. Like an idiot light. No numbers, three hash marks. Not an electrical lab ammeter. The meter is set up with a resistance ratio/balance between the shunt and meter movement so as to have an "equalibrium" value. This will show middle needle (or slightly right) when "equalibrium" is met. Needle indicates tpward D or C or light on/off when skewed. This should basically apply to 6V or 12V.
A good reliable indicator is when your lights get dim something is going wrong somewhere. When truck dies and /or won't start, something is already wrong somewhere. I never seem to spot a problem ahead of time.
An idiot light is the best idea for "GEN" indicating. Attracts more attention than a meter.
Last edited by bartamos; 11/11/2024 11:10 PM. Reason: clarification
