Air and heat

Subject:
Blower Motor Inoperative or Intermittent, Blower Speed May Drop or Blower Continues to Run After Key Off (Install a Capacitor at Blower Motor Control Module Connector)

Models:
2005 Buick Allure (Canada Only), LaCrosse
2004-2005 Pontiac Grand Prix

Supercede:

This bulletin is being revised to update Step 5 of the service procedure. Please discard Corporate Bulletin Number 05-01-39-001 (Section 01 - HVAC).

Condition

Some customers may comment on an inoperative or intermittent Heating, Ventilation and Air Conditioning (HVAC) blower motor. Others may comment that the blower motor speed may momentarily drop or that the blower motor continues to run after the key is turned off.

Cause

This condition may be caused by a voltage spike from the wiper motor. The voltage spike may cause a logic lock up in the blower motor control module that may be either momentary or permanent.

Correction

Technicians are to install a capacitor, P/N 25073556, at the blower motor control module connector using the following procedure:

1. Disconnect the negative cable from the battery.

2. Remove the right closeout/insulator panel. Refer to the Closeout/Insulator Panel Replacement-Right procedure in the Instrument Panel, Gages and Console section of SI.

3. Disconnect the wire harness connector to the blower motor control module.

4. Install a capacitor, P/N 25073556, into the blower motor control module connector using the following steps. Refer to the illustration above to locate the positive and negative leads of the capacitor.

Strip a short length of insulation from the red wire in cavity C, circuit 442, of the blower motor control module connector. Using a splice clip from the J-38125 Terminal Repair Kit, crimp the positive lead of the capacitor to the red wire.

Strip a short length of insulation from the black wire in cavity A of the blower motor control module connector. The circuit number for Buick vehicles is 1450 and for Pontiac vehicles it is 150. Using a splice clip from the J-38125 Terminal Repair Kit, crimp the negative lead of the capacitor to the black wire.

Solder both crimp connections.

Cover both crimp connections with electrical tape.

Tape the capacitor to the blower motor control module wiring harness and cover it completely with electrical tape.

5. If the customer concern was of a blower motor that continues to run after key off, then replace the blower motor control module and install the capacitor. Refer to the blower motor control module Replacement procedure in the HVAC section of SI. This condition is the only time you need to replace the blower motor control module.

6. Reconnect the blower motor control module connector.

7. Install the right closeout/insulator panel. Refer to the Closeout/Insulator Panel Replacement-Right procedure in the Instrument Panel, Gages and Console section of SI.

8. Reconnect the negative cable to the battery.

9. Verify proper operation of the blower motor.