by With rallye gauges it's less than trivial to swap stock amp gauge with volt guage for example. I saw few posts on another forum that people have had their amp gauge converted to volts by Redline Gauge Works in past. That's probably easy for those in US, but slightly less for rest of us.
After doing few searches with google it seems these ammeters are nothing more than just volt meters calibrated to millivolt range with built-in shunt to pass most of current.
Therefore perhaps one option could be removing built-in shunt and using shunt mounted in engine compartment. These would need to be wired parallel of course and gauge protected with small fuse. Big current would stay in engine bay and small current flow thru ammeter showing information we're looking for.
This is now GM did it back then to solve very same problem we have. Mopar wanted to sell more cars by burning old ones with this silly design.
Calibration is probably challenge as with such low current even small variations in wiring length and resistance due moisture in connectors would probably skew results. However, since we're not talking about any precision measurements here it shouldn't matter that much. At least what I'm mostly after is information if it's discharging or charging.
