DeeVeeEight
Fast Pedalphile
A lot of us suffer with hot air coming out of the vents. I did an internet search and found an article about a (hot water) shut off valve located behind the glove box (my car is a '79).
If you remove the glove box liner you will see a cream colored plastic plunger switch, it is rectangular in shape. The plunger is supposed to be actuated by the tab on the heat control selector cable. This plunger switch controls the heater control valve that is located on the heater hoses under the hood. There is an adjustment somewhere but I cheated and simply put a foam rubber pad on the actuator tab to help it close the plunger valve completely. A road test today was very satisfactory, the air coming out of my vents is no longer heated.
Step 1 remove glove box liner
Step 2 locate plunger switch and cable actuator
Step 3 confirm cable is operating and if it is closing the plunger switch completely
Step 4 modify the tab on the actuator. I cut a small foam rubber square from some scrap material that I had and simply cut a slit in it so I could slide the rubber square over the actuator tab. OR - you could do it right and find the adjustment for the cable and actuator (I cheated).
Step 5 confirm that the plunger switch is fully depressed when cable is moved to COLD
Step 6 reinstall glove box liner
Step 7 road test
Repair time took about 20 - 30 minutes and was very easy to do.
If you remove the glove box liner you will see a cream colored plastic plunger switch, it is rectangular in shape. The plunger is supposed to be actuated by the tab on the heat control selector cable. This plunger switch controls the heater control valve that is located on the heater hoses under the hood. There is an adjustment somewhere but I cheated and simply put a foam rubber pad on the actuator tab to help it close the plunger valve completely. A road test today was very satisfactory, the air coming out of my vents is no longer heated.
Step 1 remove glove box liner
Step 2 locate plunger switch and cable actuator
Step 3 confirm cable is operating and if it is closing the plunger switch completely
Step 4 modify the tab on the actuator. I cut a small foam rubber square from some scrap material that I had and simply cut a slit in it so I could slide the rubber square over the actuator tab. OR - you could do it right and find the adjustment for the cable and actuator (I cheated).
Step 5 confirm that the plunger switch is fully depressed when cable is moved to COLD
Step 6 reinstall glove box liner
Step 7 road test
Repair time took about 20 - 30 minutes and was very easy to do.