how to use ammeter - charging current test
1. To prevent accidental damage to the system, disconnect the negative battery cable.
2. move function switch to amps position
3. remove the wire from the charging systems output (B+)(on the generator or alternator) terminal and connect the external shunt between the output terminal and the wire which was removed, If the shunt is not permanently attached to the amp lead on your insrument, connect the green and blue clips to the small screw terminals on the shunt in such a manner as to result in up-scale readings.
4. reconnect the battery cable.
5. crank engine several times without starting to partially discharge the battery
6. start engine and run it about 2000rpm. note the highest reading just after starting the engine
caution: do not allow the external shunt to contact any exposed grounded surface while making connections or during tests.
NOTE: if the meter reads backwards, reverse the shunt connections in the step 3.
Test results
a. If the ammeter reading comes within 10 amps of rated output specified by the manufactureer, chargine current of alternator (generator) regulator system is acceptable.
b. If maximum output is 10 amps or more below the specified output, proceed to the following test to detect the cause of low charging current to either a defective alternator (generator) or misadjusted ot defective regulator.
c. DC generator only: if output current is too high, re-adjust the regulator's current limiter or replace the regulator