Message Name:

L WSHLD HEAT SPCC FAILED

Message Code:

B3-007126

Associated CAS:

L WSHLD HEAT FAIL
(Caution)

Left Windshield Secondary Power Center Contactor has failed.

• Contactor (K63)
• Time Delay Thermal Detector (K107)
• Left Windshield Temperature Controller (A157)
• Left Secondary Power Center (LSPC) (A37)
• Associated Wiring

Advisory Wire/Service Bulletin:

• AW300-30-0328 - Windshield Heat Fail CAS Messages (20501 - 20999)

Forum Articles/Infoservice/Newsletter: None

NOTE 1: The L and R Windshield Temperature Control circuits and parts (including relays) can be used for troubleshooting if needed (interchange).

NOTE 2: The Windshield Temperature Controllers and Side Window Temperature Controllers are different part numbers.

1. Confirm status of circuit breaker. If the circuit breaker is open, find out the reason before resetting. If there is other Secondary Power Center related faults in the MDC, look for commonalities with the associated power bus (L MAIN BUS).
2. Make sure WSHLD/WINDOW L PBA is ON.
3. Measure 28 VDC at LWTC A157P1 pin U.

   1. If there is 28 VDC, go to step 7.
   2. If there is no voltage, continue with next step.

4. Interchange WSHLD/WINDOW PBAs.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

5. Do wiring checks between anti-ice panel PL19 and left windshield temperature controller. Repair as required.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

6. Replace anti-ice panel PL19.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

7. Measure 28 VDC at LSPC A37 pin T7.
   CAUTION: The current could be 50 amps when the Windshield Heat is On.

   1. If there is 28 VDC, go to step 11.
   2. If there is no voltage, continue with next step.

8. Interchange contactor K63 with K64.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

9. Interchange time delay thermal detector K107 with K106.

   1. If system checks are good, do close out.
   2. If fault remains, continue with next step.

10. Interchange SPCs.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

11. Do wiring checks between LSPC and left windshield temperature controller. Repair as required.

    1. If system checks are good, do close out.
    2. If fault remains, continue with next step.

12. Interchange WTCs.
13. Do close out.