- Phillips-head screwdriver
- Flat-head screwdriver
- Pliers
- Wire cutters
- Electrical tape
- Zip ties
1. Open the hood of your GMC Safari and locate the heater box. It is located on the passenger side of the engine compartment, behind the battery.
2. Remove the two Phillips-head screws that hold the heater box cover in place.
3. Lift off the heater box cover to expose the heater core and blend door.
4. Locate the heat flap actuator. It is a black plastic housing located on the side of the heater box, near the blend door.
5. Use the flat-head screwdriver to pry open the heat flap actuator housing. Be careful not to damage the housing.
6. Remove the old actuator.
7. Clean the inside of the actuator housing with a damp cloth.
8. Insert the new actuator into the housing.
9. Snap the actuator housing closed.
10. Reconnect the electrical connector to the actuator.
11. Replace the heater box cover and secure it with the two Phillips-head screws.
12. Test the heat flap by moving the temperature control lever from hot to cold. The heat flap should move smoothly and completely between the two positions.
If the heat flap still sticks after you have replaced the actuator, you may need to adjust the blend door. The blend door is a metal flap located inside the heater box. It controls the amount of hot air that is mixed with the cold air to create the desired temperature.
To adjust the blend door, you will need to:
1. Remove the heater box cover.
2. Locate the blend door. It is located on the inside of the heater box, above the heater core.
3. Use a pliers and wire cutters to remove the zip tie that holds the blend door in place.
4. Move the blend door to the desired position.
5. Reinstall the zip tie to hold the blend door in place.
6. Replace the heater box cover.
7. Test the blend door by moving the temperature control lever from hot to cold. The blend door should move smoothly and completely between the two positions.
