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
5. Using digital multimeter, test for
Voltage Between 10 and 14 Volts -
Warm When Tempera-
voltage between harness connec-
Proceed to Test Step 6.
ture Control Panel Is Set
tor CM-C7 (WP 0009, Figure 271)
Voltage Less Than 10 Volts - Verify
On Maximum Heat - Con-
terminal A and terminal C.
cab grounds are clean and tight (WP
tinued
Voltage should be 10 to 14 volts.
0009, Figure 65). If cab ground is OK,
replace cab lower wiring harness (WP
0266).
Proceed to step 6.
6. Operate machine until engine
reaches normal operating temper-
ature (TM 5-3805-293-10).
7. Turn fan speed switch to maxi-
mum speed (TM 5-3805-293-10).
8. 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 5. Test Water Valve Actu-
ator +12 Volt Power Supply Circuit.
1. Turn ignition switch and battery
disconnect switch to the OFF
position (TM 5-3805-293-10).
2. Disconnect harness connector
CM-C1 (WP 0009, Figure 272)
from harness connector P-C16
(WP 0009, Figure 273).
3. Using digital multimeter, test for
Resistance 5.0 Ohms or Less - Pro-
continuity between harness con-
ceed to step 4.
nector CM-C1 (WP 0009, Figure
Resistance More Than 5.0 Ohms -
272) terminal 5 and harness con-
Replace cab lower wiring harness
nector CM-C7 (WP 0009, Figure
(WP 0266).
271) terminal A.
Proceed to step 6.
Resistance should be less than
5.0 ohms.
4. Disconnect harness connector R-
C1 (WP 0009, Figure 32) from
harness connector P-C3 (WP
0009, Figure 34).
0022-6