A/C - Blower Motor Chirp or Squeak

Number:
92-275-1A

Section:
1A

Date:
AUGUST 1992

Corporate Bulletin No.:
261105

ASE No.:
A7



Subject:
BLOWER MOTOR NOISE - CHIRP OR SQUEAK


Model and Year:
1988-92 C/K TRUCKS



Some 1988-92 C/K trucks up to the provided vehicle identification breakpoints may experience a blower motor noise often described as a "chirp" or "squeak". The condition has been found to be caused by oil migrating via cooling air from the motor bushings to the commutator. As oil and brush material accumulate on the commutator, the motor begins to make noise.

This condition can be corrected by replacing the motor with a new blower motor assembly (P/N 52460703), which includes an internal shield to prevent oil from reaching the commutator. The assembly also includes the motor with the impeller already installed and balanced and should be used when replacing a motor for any reason.

Before replacing the blower motor assembly, be sure to check the module seams and joints for holes or gaps that may cause a noise mistaken for blower motor noise. For example, gaps in the seam between the scroll cage and the evaporator case are often misdiagnosed as blower motor noise.

Motors containing the oil shield can be identified by a date code stamped on the motor flange. The date code is the last four digits of the 13 digit number found on the motor flange. The first three numbers of the last four digits is the Julian date. The fourth or last digit is the year. Motors containing the air shield were first built on 0842 so motors with numbers higher than 084 contain the shield.





VIN BREAKPOINTS



SERVICE PARTS INFORMATION

Part Number Description Quantity
52460703 Blower Motor and Fan Assembly 1

Parts are currently available from GMSPO.

WARRANTY INFORMATION:
For vehicles repaired under warranty use:

Labor Operation:
D1320

Use applicable labor time guide for labor hours.