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
Test Step 3. Test HVAC Control
Warm When Tempera-
Panel +12 Volt Power and Ground
ture Control Panel Is Set
Circuits.
On Maximum Heat - Con-
1. Turn ignition switch and battery
tinued
disconnect switch to the OFF
position (TM 5-3805-293-10).
2. Disconnect upper cab wiring har-
ness connector R-C22 (WP 0009,
Figure 386) from HVAC control
panel (WP 0009, Figure 385) (WP
0265).
3. Turn battery and ignition switch to
the ON position (TM 5-3805-293-
10).
4. Using digital multimeter, test for
Voltage Between 10 and 14 Volts -
voltage between harness connec-
Proceed to step 5.
tor R-C22 (WP 0009, Figure 386)
Voltage Less Than 10 Volts - Pro-
terminal 10 and machine ground.
ceed to step 6.
Voltage should be between 10 and 14
volts.
5. Using digital multimeter, test for
Voltage Between 10 and 14 Volts -
voltage between harness connec-
Proceed to Test Step 4.
tor R-C22 (WP 0009, Figure 386)
Voltage Less Than 10 Volts - Pro-
terminal 10 and terminal 12.
ceed to step 6.
Voltage should be 10 and 14 volts.
6. Turn ignition switch and battery
disconnect switch to the OFF
position (TM 5-3805-293-10).
7. Disconnect upper cab wiring har-
ness connector R-C23 (WP 0009,
Figure 277) from 24 volt converter
(WP 0009, Figure 278) (WP
0265).
8. Using digital multimeter, test for
Resistance 5.0 Ohms or Less - Pro-
continuity between harness con-
ceed to step 9.
nector R-C22 (WP 0009, Figure
Resistance More Than 5.0 Ohms -
386) terminal 12 and harness
Replace cab upper wiring harness
connector R-C23 (WP 0009, Fig-
(WP 0265).
ure 277) terminal 6.
Proceed to step 10.
Resistance should be less than 5.0
ohms.
0022-4