TM 5-2420-231-23-1
0031
Table 1. Heating, Ventilation, and A/C (HVAC) Blower Motor Does Not
Operate at One or More Speeds - Continued.
031
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
HVAC Blower Motor Does
Test Step 5. Test HVAC Blower Motor
Not Operate at One or More
High-Speed Circuit.
Speeds - Continued
1. Disconnect side console wiring
harness connector (WP 0007, Fig-
ure 130) from cab wiring harness
connector (WP 0007, Figure 129)
(WP 0170).
2. Using a digital multimeter, mea-
Resistance 5.0 Ohms or Less -
sure resistance between side con-
Proceed to step 3.
sole wiring harness connector (WP
Resistance Greater Than 5.0 Ohms -
0007, Figure 145) high speed ter-
Replace side console wiring harness
minal and side console wiring har-
(WP 0170).
ness connector (WP 0007, Figure
Install blower fan switch (WP 0172).
130) terminal A5. Resistance
Proceed to Test Step 14.
should be 5.0 ohms or less.
3. Remove headliner and right-side
cover (WP 0346).
4. Remove right lower blower duct
(WP 0350).
5. Disconnect cab wiring harness
connector (WP 0007, Figure 148)
from blower motor wiring harness
connector (WP 0007, Figure 149)
(WP 0349).
6. Using a digital multimeter, mea-
Resistance 5.0 Ohms or Less -
sure resistance between cab wir-
Replace HVAC blower motor (WP
ing harness connector (WP 0007,
0349).
Figure 129) terminal A5 and cab
Install blower fan switch (WP 0172).
wiring harness connector (WP
Connect all wiring harness connectors.
0007, Figure 148) terminal A.
Proceed to Test Step 14.
Resistance should be 5.0 ohms or
Resistance Greater Than 5.0 Ohms -
less.
Replace cab wiring harness (WP 0181).
Proceed to Test Step 14.
Test Step 6. Test for Voltage to
Blower Fan Switch.
1. Connect batteries (WP 0157) and
turn ignition switch to the on posi-
tion (TM 5-2420-231-10).
2. Using a digital multimeter, mea-
Voltage 10 to 14 Volts - Proceed to
sure voltage between side console
Test Step 7.
wiring harness connector (WP
Voltage Less Than 10 Volts - Proceed
0007, Figure 145) 12-volt supply
to Test Step 8.
terminal and machine ground. Volt-
age should be 10 to 14 volts.
0031-8
