I cant get my AC or heater to work. It blows air but wont blow hot or cold. Can this be fixed

The answer to your question is YES. You didn't state what model car you have but the problem sounds like it is with the vent system. It is operated by the vacuum system. I think if the vacuum fails for whatever reason the defrost mode will be on. I'm not sure though. I would first make sure that you have vacuum to your vent control switch.

 

One other thing I might add. If the blown air seems to change with different selections of the vents then the problem is with the temperature control and not the vent control. I think the temperature control uses the vacuum system also to make changes but I may be wrong. It may be a cable that ties to a vent door.

Glen,

 

It's a 1988 Subaru Wagon-DL. Whenever I turn on the heat it will be hot or warm, and then blows cold. In the Summer, when I turn on the AC, it blows hot air. Where can I locate the Vacumn switch? Thanks

 

Eddie

 

 

 

 

 

The answer to your question is YES. You didn't state what model car you have but the problem sounds like it is with the vent system. It is operated by the vacuum system. I think if the vacuum fails for whatever reason the defrost mode will be on. I'm not sure though. I would first make sure that you have vacuum to your vent control switch.

 

One other thing I might add. If the blown air seems to change with different selections of the vents then the problem is with the temperature control and not the vent control. I think the temperature control uses the vacuum system also to make changes but I may be wrong. It may be a cable that ties to a vent door.

The selector switch is the switch buttons you push to make the changes. This controls where the vacuum is applied to switch vent doors.

 

First, do the vent selections work as they should? Does the air come out in the floor area when you select that, etc?