Diplomat L6-225 3.7L VIN H 1-bbl (1983)
Ammeter Gauge: Testing and Inspection
Ammeter (Shunt Type) Test
The shunt type ammeter is actually a specially calibrated voltmeter. It is connected to read voltage drop across a resistance wire (shunt) between the
battery and alternator. The shunt is located either in the vehicle wiring or within the ammeter itself.
When voltage is higher at the alternator end of the shunt, the meter indicates a charge (+) condition. When voltage is higher at the battery end of the
shunt, the meter indicates a discharge ( - ) condition. When voltage is equal at both ends of the shunt, the meter reads zero.
Ammeter accuracy can be determined by comparing reading with an ammeter of known accuracy.
With engine stopped and ignition switch in RUN position, switch on headlamps and heater fan. Meter should indicate a discharge ( - ) condition.
If ammeter pointer does not move, check ammeter terminals for proper connection and check for open circuit in wiring harness. If connections and
wiring harness are satisfactory, ammeter is defective.
If ammeter indicates a charge (+) condition, wiring harness connections are reversed at ammeter.