Four 12-volt batteries connected in series-parallel supply the 12-volt electrical system
of the M915A1 truck tractor and provide 24 volts for the starter motor and blackout
lamp system. Check the batteries as described below.
Never wear jewelry while working on batteries or any
electrical systems. Metal jewelry could cause a short cir-
c u i t .
Always checks to make sure that the batteries are connect-
ed as shown in the illustration (series-parallel). Incorrectly
connected batteries can cause severe damage to the truck's
electrical system. Notify Organizational Maintenance if
batteries are not connected correctly.
Unfasten to remove battery box cover, then pull straight toward you to
clear location pins.