Climate Control Knobs suddenly quit (1 Viewer)

[Shango]

Long-time lurker, first-time poster. Have a 2000 UJZ100 that I’ve owned for 18 years.

I’m having a weird problem with my climate controls. All the buttons work (... I'm lucky with this known issue), but all three knobs suddenly stopped working. The climate control seems to be set (stuck?) on “Auto” and at a reasonable temperature. So now in the the heat of the summer, it blows cold. In the winter, it blew warm. The system auto-regulates to the set temperature — so the fan’s speed adjusts, for example.

But the knobs don't work. One day they did, and the next day they didn't.

The AC on/off button works, so when the system is cooling, I can select “off” and air does get warmer so I suppose the compressor does shut off. The fan motor continues to blow. There are no noises when adjusting the knobs (no clicking of baffles or anything).

I’d like to recover the functionality of the three knobs (temperature, directions, fan speed).

What do you think the problem is? How do I diagnosis it?

 

[Patassa]

Have you tried giving it a good knock?

 

[Shango]

Have you tried giving it a good knock?

Yes -- initially in my own frustration and then to lovingly encourage it.

The weirdness of the problem makes me think that there's a fault on a circuit board. Doesn't seem like a mechanical problem as all of the knobs quit at the same time. But I don't know.

 

[Patassa]

What about popping the control panel out and cleaning the connections really well?

 

[Shango]

Thanks. Good idea -- and I have trim tools and electrical contact cleaner already on hand.

Looking at part diagrams and various videos, it looks to me like I remove the knobs, remove the retaining nuts, remove the bezel, and then open up the AC Amplifier Assembly. And then try not to break plastic retaining clips on the connectors. Clean. Re-assemble. Pray. Test.