Remove all jewelry such as rings, dog tags, bracelets, etc. If jewelry contacts battery terminal, a direct
short may result in instant heating of tools, damage to equipment, and injury or death to personnel.
( 1 ) Regulator test (open).
Alternator should be mounted in vise, shaft rotating at 3000 rpm, with jumper wire installed between B
and field terminal.
Measure voltage at terminal A. Meter should read approximately 24 volts.
Increase rpm to 4000. (To the right [clockwise] as viewed facing the fan.)
Measure voltage at terminal A. Voltage should increase to 24 to 25 volts.
Readings other than these indicate alternator is open and should be replaced.