Heater out of control

[davy83]

any one had their heater jump from too cold to too hot with one click of the temperature knob? It get hot ok, and the AC blows cold if you turn it to the extremes but if you sit it in the middle setting it just takes one click of the dial it goes from hot to cold. I pulled the little temperature sensor out thinking the wee fan inside was broken but that all seems ok. any thoughts? The AC control unit is expensive to replace so i am hoping its something else!

 

[williamsmix]

Yes, it is expensive. I’ve successfully reset mine (on the 3200) a few times using this routine, which maybe worth a try / a starting point before you start pulling things apart(?) …

With the ignition to OFF, turn the temp dial to LO, the fan dial to AUTO and the air direction dial to AUTO.

Hold down the 'recirculate' and 'econ' buttons together.

Turn the ignition to ON and wait until the lights on the 2 buttons flash in unison, then let go of the buttons. Once the lights have stopped flashing, the system is reset...

 

[davy83]

Yes, it is expensive. I’ve successfully reset mine (on the 3200) a few times using this routine, which maybe worth a try / a starting point before you start pulling things apart(?) …

With the ignition to OFF, turn the temp dial to LO, the fan dial to AUTO and the air direction dial to AUTO.

Hold down the 'recirculate' and 'econ' buttons together.

Turn the ignition to ON and wait until the lights on the 2 buttons flash in unison, then let go of the buttons. Once the lights have stopped flashing, the system is reset...

Thnks for this. And the stupid thing is I think I have done this previously many years ago and forgot about it. I also seem to remember there is a diagnostic routine that gives you error messages relating to the heater, i must look that up and try that too!! Doooh old age getting the better of me i suspect.

 

[spkennyuk]

Thnks for this. And the stupid thing is I think I have done this previously many years ago and forgot about it. I also seem to remember there is a diagnostic routine that gives you error messages relating to the heater, i must look that up and try that too!! Doooh old age getting the better of me i suspect.

The same routine also displays any error code alpha numerival by 2 pairs of two digits per error. The codes are listed in the handbook and on the forum.

It displays where the gear number is shown. AA00 is no error.

 

[xavier939]

Yeah, I’ve had a similar issue before. In my case, it turned out to be the blend door actuator. It wasn’t moving smoothly, so it would jump between hot and cold instead of mixing properly. Might be worth checking that out before replacing the whole control unit. Hope you get it sorted!

 

[davy83]

Yeah, I’ve had a similar issue before. In my case, it turned out to be the blend door actuator. It wasn’t moving smoothly, so it would jump between hot and cold instead of mixing properly. Might be worth checking that out before replacing the whole control unit. Hope you get it sorted!

Don't suppose oyu remember how much work it took to get in at that?