Hello.
I have a 98 Lariat. I'm wondering if anyone ever experienced this problem if so please shed some light on it. Thanks.

I'm driving with the a/c on, all of a sudden the air becomes hot as if the heat is on. I made my sure my temp switch was on cold, still heat is coming thru the vents. Turn a/c off then back on now it's cold again few minutes later back to hot.
What is going on here?

Thanks again for any help!

 

Check the compressor if it is still engage when it blows hot. Look at the drivebelt and check if the compressor is slipping.

 

Hello wolves. I found the problem. It's my blend door next to the heater core.