Hey guys. I've got a problem with my A/C changing from cold to hot, but it's not just when the A/C is on. It's all the time.

Let me explain. I have the A/C on, set to recirculate, and on the coldest setting. All of the sudden the HEATER turns on. I can hear it turn on. I turn the temperature control to the middle and then all the way back to the coldest setting to get cold air again. This is different from what I've heard about before, because this also happens if I don't have the A/C on. I can have the fan turned off with fresh air blowing into the car and the temp control all the way cold, and it will still fluctuate between hot and cold.

Anyone have any ideas. I'm getting ready to take it in and I just want some idea of whats going on.

Oh, and I just hit 52k miles.

 

What I would do (unsolicited advice here) is this:

1. Reset ECU (do this by disconnecting the battery for 15 min, then reconnecting it)
2. Perform A/C reprogram (with car off, hold down the FRONT defrost button and the recirc/fresh button, then turn the key to the ACC position. Keep the key there for 3 seconds, then turn it to ON for three seconds- all the while you don't move your other hand. The REAR defrost button should blink three times. Then turn your car on).

I had a similiar problem where my car just decided on its own what temperature my air should be. I did the above fix, and she's been working great ever since! Oh, and when you turn the temp to the very coldest, it now automatically goes into recirc (max A/C)!

 

Yep had the exact same issue, dealer just order a new control unit/****.

Did the AC reprogram with no results and wasn't going to undo the ECU since the dealer was already looking at it.

Let you know if it works, but it is covered under warrenty regardless.

 

Well, I just got a call from the dealer. My A/C and Radio Control panels are both fried. He said they tested them both and they are both shorted. He wouldn't replace one without the other. Ready for this quote:

Radio Control panel : $462.00
AC control panel: $285.00
Labor: $133.50
Total with tax: $953.14.

I asked him to see if there is anything they can do to help with the price since I'm only at 54k miles. I'll let you guys know what happens.

Cel

 

Well dealership just called back. The service writer Dave is awesome. They are going to get the parts, I'm getting the labor. Great deal. Munday Mazda on 1960 in Houston. Dave is the man to talk to.

Cel