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 11. Test Blower Fan Switch
Not Operate at One or More
12-Volt Supply for a Short Circuit.
Speeds - Continued
1. Remove rear instrument panel
right-side cover (WP 0176).
2. Disconnect side console wiring
harness connector (WP 0007, Fig-
ure 24) from rear main chassis wir-
ing harness connector (WP 0007,
Figure 25).
3. Using a digital multimeter, test for
Continuity - Replace side console
continuity between side console
wiring harness (WP 0170).
wiring harness connector (WP
Install blower fan switch (WP 0172).
0007, Figure 145) A/C compressor
Install new blower fuse (TM 5-2420-
12-volt supply terminal and
231-10).
machine ground. There should be
Proceed to Test Step 14.
no continuity.
No Continuity - Proceed to step 4.
4. Remove instrument panel front
covers (WP 0174).
5. Disconnect front console wiring
harness (WP 0007, Figure 5) from
front main chassis wiring harness
(WP 0007, Figure 6) (WP 0162).
6. Using a digital multimeter, test for
Continuity - Install blower fan switch
continuity between front console
(WP 0172).
wiring harness connector (WP
Replace front console wiring harness
0007, Figure 5) terminal N6 and
(WP 0162) and install new blower fuse
machine ground. There should be
(TM 5-2420-231-10).
no continuity.
Proceed to Test Step 14.
No Continuity - Replace main chassis
wiring harness (WP 0162).
Install blower fan switch (WP 0172).
Install new blower fuse (TM 5-2420-
231-10).
Proceed to Test Step 14.
Test Step 12. Test Fan Speed Circuits
for a Short.
1. Disconnect side console wiring
harness connector (WP 0007, Fig-
ure 130) from cab wiring harness
connector (WP 0007, Figure 129)
(WP 0170).
0031-15
