HEATER/A/C BLOWER OPER ON 3- SPD INSTALL REDESIGN RESISTOR

SUBJECT: HEATER/A/C BLOWER APPEARS TO OPERATE ON THREE SPEEDS ONLY (INSTALL REDESIGNED RESISTOR)

VEHICLES AFFECTED: 1992 M/L VANS WITH A/C (RPO C60) CHEVROLET ASTRO GMC SAFARI

Owners of some 1992 M/L vans with air conditioning (RPO C60) may comment that the fan lever on the heater control panel does not allow for a comfortable range of air flow settings. The selector lever was designed to allow for five comfort positions. Starting from the "OFF" position the air flow is increased through four phases by moving the lever to the right, toward "HIGH".

The customer may comment that first two positions only have a slightly noticeable difference in air flow. Then, when the lever is moved to the third position, the air flow increases dramatically. To correct this condition, a new resistor (P/N 526897) may be installed.

SERVICE PROCEDURE:

Perform a diagnosis of the blower system (see the flow chart in section 1A-13 "BLOWER INOPERATIVE" of Service Manual X-9230). If the diagnosis indicates a malfunctioning blower speed switch, install a new resistor - DO NOT replace the switch.

1. Disconnect the harness connector from the resistor (Figure 1).

2. Remove the two screws which secure the resistor to the evaporator case.

3. Remove the resistor from the evaporator case.

4. Install a new resistor (P/N 526897), into the evaporator case.

5. Install the two screws which secure the resistor to the evaporator case.

6. Connect the harness connector to the resistor.

7. Check for proper circuit operation.

SERVICE PARTS INFORMATION:

Part Number Description ----------- ----------- 526897 Resistor

For vehicles repaired under warranty use:

Labor Operation: D1002 - Resistor, Blower Motor - Replace Labor Time: 0.3 hours.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.