Remove rings, bracelets, watches, necklaces, and any other jewelry before working around vehicle. Jewelry can catch on
equipment and cause injury or short across electrical circuit and cause severe burns or electrical shock.
Battery acid is harmful to skin and eyes. Always wear eye protection when working with batteries.
(1) Remove battery cover (Para 8-42).
(2) Disconnect negative battery cable from
negative side of battery (Para 8-42).
(3) Remove four screws from heater and
air conditioner temperature control
(4) Raise heater and air conditioner
temperature control panel out to reach
heater/air conditioner switch.
(5) Set multimeter to volts dc.
(6) Connect multimeter positive lead (+) to
cab blower switch where jumper wires
connect pins 7, 8 and/or 5.
(7) Connect multimeter negative lead () to
known good ground.
(8) Turn engine start switch to ON position,
8 1 2 3
BUT DO NOT START ENGINE
7 4 5 6
(9) Turn heater/air conditioner switch to
HEAT (TM 10-3930-673-10).
(a) If voltage is present, go to Step 3
of this fault.
(b) If voltage is not present, repair
jumper wire (Para 8-48).
(10) Turn heater/air conditioner switch OFF
(11) Turn engine start switch to OFF
position (TM 10-3930-673-10).
CAB BLOWER SWITCH
IR CONDIS IONER