AC / Defrost - won't blow hot air (1 Viewer)

[toyogi]

My AC gets nice and cold but when I go to defrost mode with AC on, the temp with get less cold but not hot when I turn the slider bar to hot. Also heater does not get super hot in from vs. heater in the rear.

93' 80

Thoughts?

Thanks

 

[KiwiDan80]

Get a helper to move the hot/cold slide from cold to hot while you watch the heater tap on the fire wall and see if it moves. If not pull the glove box out and look in towards the top center of the heater box and you should just see the electric servo that moves the blend door and also pulls the control cable for the heater tap. Once again move the heat slide and watch and listen for movement, if the servo is trying to move the cable is probably seized or broken. I have replaced a few now and it is a prick of a job.

 

[Dave 2000]

True a crap job but seemingly a little easier on the right hand drive, half of the dash board had to come out? If you need heater NOW due to weather, perhaps you could disconnect the cable at the tap at the bulkhead, and tie it in the hot position temporarily?

regards

Dave

 

[quasi]

This won't work, as the servo motor that controls the cable, also closes a flap that would allow air to pass over the heater core. Remove the radio to access the servo

 

[CJF]

Seems to me all three of you are on the wrong track if he has heat from the rear.

 

[Cruzerman]

Seems to me all three of you are on the wrong track if he has heat from the rear.

Nope. Seems right on track. The symptoms of the flapper not working is that the heater control valve is open, you have rear heat, but no front heat. I had the same issue. My issue was a cold solder joint on the temp slider. There is a thread on it. I pulled the controls, re-soldered the slider, and now it works (most of the time). Figured it was easier to try than replacing the servo.

 

[CJF]

The symptoms of the flapper not working is that the heater control valve is open, you have rear heat, but no front heat.

Ok, that I can believe. (Or a clogged front heater core if the flapper is working properly.)