Heater - Lack of Heat

Article No.
92-4-13

02/12/92

HEATER - LACK OF TEMPERATURE BLEND DOOR CAM SPRING DOES NOT ALLOW BLEND DOOR TO SEAT PROPERLY - VEHICLES BUILT PRIOR TO 11/11/91

LIGHT TRUCK:
1992 BRONCO, F SUPER DUTY, F-150-350 SERIES, F-47

ISSUE:
There may be a lack of heat because the temperature blend door cam spring, which was designed to provide assistance in control effort, may not allow the temperature blend door to seat properly in the high heat position.

ACTION:
Remove the temperature blend door cam spring. Refer to the following procedure for service details.

NOTE:
CHANGING THE THERMOSTAT WILL NOT INFLUENCE POOR HEATER PERFORMANCE WHICH RESULTS FROM THE PRESENCE OF THE CAM SPRING.

1. Remove the glove box door and the glove box. Refer to the 1992 F-Series and Bronco Service Manual. Page 01-12A-B, for the removal procedure.

2. Remove the temperature blend door control cable using Cable Removal Tool (D91T-18532-A).

3. Remove the temperature blend door control cam from the top of the plenum and remove the spring. A ratcheting box wrench is recommended for removing the cam hold down screw.

NOTE:
ON VEHICLES WITH A REAR ANTI-LOCK BRAKE SYSTEM, IT MAY BE NECESSARY TO REMOVE THE RABS CONTROL MODULE TO GAIN ACCESS TO THE PLENUM. REFER TO THE 1992 F-SERIES, BRONCO SERVICE MANUAL, SECTION 06-09, FOR THE REMOVAL PROCEDURE.

4. Install the cam on the plenum and connect the temperature blend door control cable. Make sure the cable is adjusted properly so the door seats firmly at each end of its travel.

5. Install the RABS module, if removal was necessary.

6. Install the glove box and glove box door.

7. Check the system operation.

OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME

920413A Remove Temperature Blend 0.4 Hr.
Door Cam Spring.

DEALER CODING
CONDITION
BASIC PART NO. CODE
18552 41

OASIS CODES: 208000, 208100