HVAC Blower Motor - Noisy or Inoperative

BULLETIN NUMBER:
SB99-12-S001

ISSUE DATE;
JANUARY 1999

GROUP:
HEATING & A/C

1991-97 RODEO (UC) HVAC BLOWER MOTOR: WATER INTRUSION

AFFECTED VEHICLES
1991-97 Rodeo (UC) models.

SERVICE INFORMATION

Condition:
Some affected vehicles may experience one or more of the following conditions:

^ Noisy blower motor operation
^ Loss of one or more fan speeds
^ Reduced fan speed
^ Inoperative blower motor
^ Partial or complete failure of the blower resistor

Possible Cause:
Moisture may have entered the blower motor assembly if the passenger side cowl screw is either installed incorrectly or insufficiently tightened.

Correction:
Using the information outlined in this bulletin, inspect the blower system for any signs or possibility of water intrusion. In addition, service the blower system using published procedures in the Workshop Manual.

SERVICE PROCEDURE
Follow the steps below to verify if moisture is entering the vehicle above the blower motor assembly:

1. Remove the blower motor assembly.
^ Inspect for rust on the blower motor shaft.





2. Introduce water to the vent cowl cover area. (Figure 1)





3. Visually inspect up through the fan case where the blower motor assembly was pre. viously removed. (Figure 2)

4. If moisture can be seen entering the cab, the leak must be repaired. Verify that the passenger side cowl screw is correctly tightened and apply room temperature vulcanizing (RTV) rubber sealant to seal the leak if necessary.

NOTE
If a repair is made to the blower fan circuit and moisture continues to enter the vehicle above the blower motor assembly, a repeat failure is possible.

Refer to the appropriate published Workshop Manual and Flat Rate Manual to service the blower system.