1989 Honda FL400R Pilot Service Manual, Page 229Get this manual
BATTERYCHARGING SYSTEM REGULATED VOLTAGEAMPERAGE INSPECTION NOTE
Be sure the battery is in good condition before performing
this testWarm up the engine to normal operating temperature
If the engine must be running to do some work, make sure the area is well ventilatedI'lever run the engine in an enclosed area1'he exhaust ('ontains poisonous carbon monoxide gas that can cause loss of' consciousness and may lead to death
Stop the engineConnect the voltmeter positive probe to the battery positive terminal and negative probe to the negative
terminal
Disconnect the red wire connectorConnect an ammeter between the red wire terminals
CAUTION
Be while not to let the battery positive cable contact the frame
Restart the engine and allow it to idle, then increase the engine speed graduallyThe voltage and amperage should be controlled as specified below: