TM 5-3805-293-23-2
0022
Table 1. Cab Heating, Air Conditioning, and 12 Volt Power Inverter Troubleshooting Procedures - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. Heater Does Not Blow
9.
Using digital multimeter, test for
Resistance 5.0 Ohms or Less -
Warm When Tempera-
continuity between harness con-
Replace 12 volt power inverter (WP
ture Control Panel Is Set
nector R-C22 (WP 0009, Figure
0265).
On Maximum Heat - Con-
386) terminal 10 and harness
Connect upper cab wiring harness
tinued
connector R-C23 (WP 0009, Fig-
connector R-C22 (WP 0009, Figure
ure 277) terminal 5.
386) to HVAC control panel (WP
Resistance should be less than
0009, Figure 385) (WP 0265).
5.0 ohms.
Proceed to step 10.
Resistance More Than 5.0 Ohms -
Replace cab upper wiring harness
(WP 0265).
Proceed to step 10.
10. Operate machine until engine
reaches normal operating temper-
ature (TM 5-3805-293-10).
11. Turn fan speed switch to maxi-
mum speed (TM 5-3805-293-10).
12. Turn temperature control to the
No Warm Air From Air Vents -
warmest setting and verify warm
Repeat troubleshooting from the
air exiting from air vents.
beginning.
Warm Air From Air Vents - Trouble-
shooting Complete.
Test Step 4. Test Water Valve Actu-
ator +12 Volt Power and Ground
Circuits.
1. Connect upper cab wiring har-
ness connector R-C22 (WP 0009,
Figure 386) to HVAC control
panel (WP 0009, Figure 385) (WP
0265).
2. Disconnect cab lower wiring har-
ness harness connector CM-C7
(WP 0009, Figure 271) from water
valve actuator (WP 0009, Figure
270) (WP 0294).
3. Turn battery disconnect switch
and ignition switch to the ON posi-
tion (TM 5-3805-293-10).
4. Using digital multimeter, test for
Voltage Between 10 to 14 Volts -
voltage between harness connec-
Proceed to step 5.
tor CM-C7 (WP 0009, Figure 271)
Voltage Less Than 10 Volts - Pro-
terminal A and machine ground.
ceed to Test Step 5.
Voltage should be 10 to 14 volts.
0022-5
