A/C - Updated Temperature Control Cables
GMC NUMBER: 88-T-21GROUP: 1A - Heating & Ventilation
DATE: June, 1987
CORPORATE
NUMBER: 861101
SUBJECT: TEMPERATURE CONTROLCABLES
MODELS: 1988 C/K MODELS WITHOUT AIR CONDITIONING
Some 1988 C/K models without air conditioning may have temperature control cables that will not adjust properly. This condition is due to the cable adjustment ratchet having insufficient tension. Vehicles with this condition will experience either of the following symptoms:
a) Cool air from the heater or defroster vents when the temperature lever is in the full warm position.
b) Warm air from the heater or defroster vents when the temperature lever is in the full cool position.
To repair this condition, new temperature control cables have been released.
P/N 15606998 - Base Heater P/N 15606999 - Heavy Duty Heater (RPO C42)
CABLE ADJUSTMENT PROCEDURE
^ Install new cable to heater control assembly and heater case.
^ To adjust the cable, move temperature lever to the full warm position.
Notice: Some resistance and a ratcheting noise will be noticed toward the end of lever travel. This resistance and noise will be experienced during the first adjustment only. Once the lever is moved to the full warm position, correct adjustment has been achieved.
Effective with the following VIN breakpoints new cables have been installed in production.
Oshawa Chevrolet J1132635
GMC J1511630
Pontiac East Chevrolet JE117213
GMC JE505233
Fort Wayne Chevrolet JZ116479
GMC JZ504882