Only One Wiper Speed is Available

TASK 30-45-00-810-802-A
Only One Wiper Speed is Available

1. Possible Causes

wiring from pin 2 of the circuit breaker 4DB1(4DB2) to pin A of the wiper motor converter 6DB1(6DB2)
wiring from pin C of the wiper motor converter 6DB1(6DB2) to pin 3 of the WIPER control switch 5DB1(5DB2)
CTL SW-WIPER, CAPT [5DB1]
CTL SW-WIPER, F/O [5DB2]
MOTOR CONVERTER-WIPER, CAPT [6DB1]
MOTOR CONVERTER-WIPER, F/O [6DB2]
wiring from pin E of the wiper motor converter 6DB1(6DB2) to pin 4 of the WIPER control switch 5DB1(5DB2)

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 30-45-00-720-001	Functional Test of the Windshield Rain Protection
ASM 304501
AMM 30-45-51-000-001	Removal of the Wiper Motor Converter
AMM 30-45-51-400-001	Installation of the Wiper Motor Converter

3. Fault Confirmation
Subtask 30-45-00-720-052-A

A. Test
Do the functional test of the windshield rain protection AMM 30-45-00-720-001.

4. Fault Isolation
Subtask 30-45-00-865-051-A

A. Table of the circuit breakers used in this procedure:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
122VU	ANTI ICE/F/O/WIPER	4DB2	W12
122VU	ANTI ICE/WIPER/CAPT	4DB1	X12

Subtask 30-45-00-810-051-A

B. If there is only one speed available:

do a check for 28VDC at pin A/A of the wiper motor converter 6DB1(6DB2) ASM 304501.

(1) If there is no 28VDC:

do a check and repair the wiring from pin 2 of the circuit breaker 4DB1(4DB2) to pin A of the wiper motor converter 6DB1(6DB2)

(2) On the panel 21VU(22VU):

set the WIPER control switch to SLOW.

(3) If there is 28VDC:

do a check for ground at pin C of the wiper motor converter 6DB1(6DB2).

(a) If there is no ground signal:

do a check of the wiring from pin C of the wiper motor converter 6DB1(6DB2) to pin 3 of the WIPER control switch 5DB1(5DB2).

1 If there is no continuity:

repair the above wiring.

2 If there is continuity:

replace the CTL SW-WIPER, CAPT [5DB1] ( CTL SW-WIPER, F/O [5DB2] ).

(b) If there is a ground signal:
replace the MOTOR CONVERTER-WIPER, CAPT [6DB1] ( MOTOR CONVERTER-WIPER, F/O [6DB2] ) AMM 30-45-51-000-001 and AMM 30-45-51-400-001.
(4) On the panel 21VU(22VU):

set the WIPER control switch to FAST.

(5) If there is 28VDC:

do a check for ground at pin E of the wiper motor converter 6DB1(6DB2).

(a) If there is no ground signal:

do a check of the wiring from pin E of the wiper motor converter 6DB1(6DB2) to pin 4 of the WIPER control switch 5DB1(5DB2).

1 If there is no continuity:

repair the above wiring.

2 If there is continuity:

replace the CTL SW-WIPER, CAPT [5DB1] ( CTL SW-WIPER, F/O [5DB2] ).

(b) If there is a ground signal:

replace the MOTOR CONVERTER-WIPER, CAPT [6DB1] ( MOTOR CONVERTER-WIPER, F/O [6DB2] ) AMM 30-45-51-000-001 and AMM 30-45-51-400-001.

Subtask 30-45-00-720-053-A

C. Do the test given in Para. 3.

[Rev.8 from Aug 2018] 2026.04.04 04:29:44 UTC