Momentary Loss of HVAC Blower Motor Operation While Adjusting Power Seats (Install Capacitor in HVAC Blower Motor Control Processor Circuit)

Some customers may comment on a momentary loss of the HVAC blower motor operation.

Most customers may not relate the split-second loss of the HVAC blower motor operation with the operation of the power seat.

Transient currents caused by the operation of the front power seats may momentarily interrupt the HVAC blower motor operation.

1. Open the hood.
2. Remove the underhood electrical center cover.
3. Remove the 40 AMP BLWR fuse.
4. Remove the right IP insulator panel. Refer to Insulator Replacement - Instrument Panel (IP) (SI Document ID #871654).
5. Disconnect the three-wire electrical connector from the blower motor control processor.
6. Remove the insulation tape from the harness end.



7. The indentation on the capacitor indicates the positive side of the capacitor.

Important: 

•	The blower motor processor negative wire is the BLACK wire, CKT #1050.

•	The blower motor processor positive wire is the RED wire, CKT #542.

•	DO NOT use the PURPLE wire, CKT #760.

•	It is recommended NOT to cut the wires in CKT #1050 and #542 when installing the capacitor.




8. Install the 330uf 50V capacitor as shown above using the procedure below.

Important: Stagger the cuts in the wire installation to allow room for the capacitor.

9. Cut and pull back the wire insulation ONLY on CKT's #542 and #1050.
10. Install the positive side (indentation side) of capacitor, P/N 25073556, on the RED wire, CKT #542 and crimp with P/N 821240 from Terminal Kit J 38125, Tray 18 using the appropriate crimping tool.
11. Install the negative side (no indentation) of capacitor, P/N 25073556, on the BLACK wire, CKT #1050 and crimp with P/N 821240 from Terminal Kit J 38125, Tray 18 using the appropriate crimping tool.
12. Solder the crimps using 60/40 rosin core solder to the opening in the back of the clip. Follow the manufacturer's instructions for the solder equipment.
13. Tape both crimped/soldered ends with electrical tape.
14. Tape the capacitor to the harness.
15. Retape the harness.
16. Install the electrical connector to the blower motor processor.
17. Install the IP insulator panel. Refer to Insulator Replacement - Instrument Panel (IP) (SI Document ID #871654).
18. Install the 40 AMP BLWR fuse in the underhood electrical center.
19. Install the electrical center cover.
20. Close the hood.
21. Test the blower motor operation while moving the power front seat fore and aft.

Parts are currently available from GMSPO.

For vehicles repaired under warranty, use:

*This labor operation number is for bulletin use only.