Brake Fans Inoperative on the Wheel 1 #amp# 2

TASK 32-48-00-810-802-A
Brake Fans Inoperative on the Wheel 1 & 2

1. Possible Causes

wiring between the left brake fan contactor (5GS) at pins A/A1, B1, C1 and the first terminal block
wiring from the left brake fan contactor (5GS) pin A/X2 to the first terminal block
wiring from the left brake fan contactor (5GS) pin A/X1 to the first terminal block
CONTACTOR-BRK FAN, L (5GS)
wiring from the left brake fan contactor (5GS) to the circuit breaker (1GS)
C/B-HYDRAULIC/BRK FAN/WHEELS/1 AND 2 [1GS]
MOTOR ASSY-BRK FAN,WHEEL AXLE 2 [9GS]
MOTOR ASSY-BRK FAN,WHEEL AXLE 1 [7GS]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 32-48-00-710-001	Functional Test of The Brake Cooling System
ASM 324801
AMM 32-48-51-000-005	Removal of the Fan Assy
AMM 32-48-51-400-005	Installation of the Fan Assy

3. Fault Confirmation
Subtask 32-48-00-710-052-A ** ON A/C NOT FOR ALL

A. Test
(1) Do the operational test of the brake cooling system AMM 32-48-00-710-001.
(a) If the circuit breaker (1GS) trips:

(2) Make sure that the fans do not operate on the left gear.

4. Fault Isolation
Subtask 32-48-00-810-051-A ** ON A/C NOT FOR ALL

A. If the test confirms the fault:

(1) If the circuit breaker (1GS) is closed:

Do a check for 115VAC at pins A/A1, B1, C1 of the left brake fan contactor (5GS) ASM 324801.

(a) If there is 115VAC:

Do a check of the wiring between the left brake fan contactor (5GS) at pins A/A1, B1, C1 and the first terminal block ASM 324801.

1 If there is no continuity:

2 If there is continuity:

Do a check for a ground signal at pin A/X2 of the left brake fan contactor (5GS) ASM 324801.

a If there is no ground signal:

Repair the wiring from the left brake fan contactor (5GS) pin A/X2 to the first terminal block ASM 324801.

b If there is a ground signal:

Do a check and repair the wiring from the left brake fan contactor (5GS) pin A/X1 to the first terminal block ASM 324801.

(b) If there is no 115VAC:

1 If the fault continues:

Do a check of the wiring from the left brake fan contactor (5GS) to the circuit breaker (1GS) : pins A/A2, B2, C2 to pins A2, B2, C2 ASM 324801.

a If there is no continuity:

b If there is continuity:

(2) If the circuit breaker (1GS) is open:

(a) If the circuit breaker trips:

Replace the CONTACTOR-BRK FAN, L (5GS) or MOTOR ASSY-BRK FAN,WHEEL AXLE 2 [9GS] or MOTOR ASSY-BRK FAN,WHEEL AXLE 1 [7GS] , AMM 32-48-51-000-005 and AMM 32-48-51-400-005

1 If the fault continues:

Do a check for a short to ground at:
. the wiring from the circuit breaker (1GS) to the left brake fan contactor (5GS) : pins A2, B2, C2 to pins A/A2, B2, C2
. the wiring from the left brake fan contactor (5GS) pins A/A1, B1, C1 to the wheel axle 1, brake-fan motor assy (7GS) pin A/1,2,3.
. the wiring from the left brake fan contactor (5GS) pins A/A1, B1, C1 to the wheel axle 2, brake fan motor assy (9GS) pin A/1,2,3.
ASM 324801.

a If there is a short to ground:

b If there is no short to ground:

(b) If the circuit breaker (1GS) stays closed and if the fault continues:

Subtask 32-48-00-710-053-A ** ON A/C NOT FOR ALL

B. Test
Do the test given in Para. 3.A.(1).

[Rev.8 from Aug 2018] 2026.04.04 04:31:47 UTC