Compressor running with heat on...

[Chrispbrown36]

So I got motivated Friday and got the a/c up and going on the old truck. It cooled nicely but some of the duct work was off and I knew I had to change the fan switch so I tore into the dash today. After pulling it apart I was checking to make sure the blend door was closing all the way when I noticed that the a/c compressor would continue to run even after I had changed it over to heat or defrost. What might be causing this?

[cerial]

Are you sure your switch is working and cutting power to the ac compressor? Some of these switches like to do there own thing.
I would hit up a junk yard and plug in a different switch.


If you wired something to the key on that is connected to the heating controls you could be bypassing the switch all together unintentionally.


For the short term need to get to work tomorrow kind of deal just wire up a temporary toggle switch.

[Prong]

If you're running factory air, the compressor will run on defrost mode to dehumidify the air.

[Chrispbrown36]

It's all stock, so no bypassing anything. A/C, defrost, heat....compressor runs like it should for a/c but continues to cycle on everything else. This is my play truck, so I have time to figure out what is really wrong. What switch are you referring to Cerial?

[Chrispbrown36]

I messed around with it a little more today and it is kicking on when the defrost is on but not with the heat. I also managed to fix the high fan speed....ac relay was the culprit there. Thanks for the advice everyone.