DISASSEMBLY - TM-9-4120-430-140160

TM 9-4120-430-14

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1. Verify labels on motor wiring to wire list (WP 0038 00) and disconnect the motor wiring.

2. Loosen clamp holding temperature selector switch sensing bulb, move bulb to clear housing. Refer to figure 1, front

view illustration.

3. Remove two screws (1, Figure 2) and lockwashers (2) and remove close off angle (3) from firewall bracket (4) of the

inner housing bulkhead. Refer to figure 2, exploded view.

4. Remove four screws (1, Figure 1) securing the fan and motor base (2) to the unit.

5. Lift out fan and motor assembly from the unit housing.

DISASSEMBLY

1. Loosen setscrew (5, Figure 2) on flat side of motor shaft and slide off impeller (6) from motor shaft.

2. Remove motor mounting bracket (7) with motor (8) by removing four hex head screws (9) and lockwashers (10).

3. Remove four screws (11) and lockwashers (12) securing blower housing (13) to evaporator blower rails (14) and

(15).

4. Remove four screws (16) and lockwashers (17) to loosen inlet rings (18) from each end of blower housing (13).

5. Carefully remove impeller (6) from blower housing (13) through housing opening.

6. Remove four locking nuts (19) and flat washers (20) from motor mounting screws (21) and flat washers (22) that

secure motor (8) to motor mounting bracket (7).

INSPECTION

1. Inspect fan rings (18), impeller (6) and fan housing (13) for visible out-of-round conditions, dents, burrs and nicks.

2. Replace defective items.

3. Check impeller (6) for damaged or bent vanes. Straighten or replace impeller (6), if required.

4. Inspect exterior case of motor for cracks, dents, oil, and evidence of overheating or any other abnormalities. Replace

defective motor.

TEST

1. Turn motor (8) shaft by hand and listen for clicking sounds that indicate bad bearings. Replace motor if motor

bearings are bad.

2. If the shaft cannot be rotated, the bearings may have seized. Replace motor.

3. Test the thrust bearings by attempting to push and pull the motor shaft axially.

4. If end play is excessive (i.e., can be felt on manual push-pull), the thrust bearings and shims are worn beyond limits

and motor should be replaced.

5. Use a multimeter or continuity tester to check continuity between leads. See wiring diagram (WP 0038 00). Check

to be sure that continuity exists between leads. This means that open circuits do not exist. Replace motor if either

open or short circuits exist.

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