Dual Climate Control Issues

[Traskin]

I have a 2000 GT with the automatic dual climate control. Its had its share of gremlins that ranged from ignorable to annoying, but the latest can not go unpunished. When the weather this year started cooling, I noticed that the heater fan wouldn't kick in until the engine warmed up a bit, then it would fire up. Thought it was a bit of a courtesy so frigid air wasn't pounding me in the face. I also noticed that the rear window defrost wasn't working occasionally. As the weather got colder, the heater fan stopped working altogether and the rear window defrost stopped working too. All the research I did on the internet pointed to the ignition switch, so I replaced that. That wasn't the fix. So I'm looking for input on solutions.

SYMPTOMS:
Fan will not turn on.
Vents move when I hit different buttons
Heat comes through when the vehicle is in motion​
Rear defrost doesn't work although CC says it is on
All lights work on the head unit in conjunction with buttons
Control unit works as if everything is ok (albeit metric)

Has anyone ever had the control unit go out? Is this something anyone out there has experienced? Can I plug in manual controls?

Thanks!!!!

 

[Scottydoggs]

sounds like air in the heater core. when the cars warmed up touch both heater hoses if one or both are cold you got air trapped in there.

as far as the fan working? does it work on speed 5 only? or not at all?

defroster, check the fuse box.

 

[Traskin]

Thanks for the response. This is on the digital dual climate control, so there is not a 1-5 for the fan. The rear window defrost is an intermittent problem that turned out to be linked to the times when the blower was not turning on.

 

[Scottydoggs]

your fan has speeds, they all do. so do they all work or not?

 

[Traskin]

The fan doesn't turn on at all.

 

[Scottydoggs]

test for power at and after the resistor to the fan.