HVAC Automatic Climate Control is Either Hot or Cold (1 Viewer)

[GringoBob]

The automatic climate control system in my 97 40th Anniversary LC can be set to full heat or full cold only ...nothing in between (like warm) ...when in automatic or manual setting. So my only adjustments are Hot, Cold and fan speed.

Any explanations or suggestions ?

Thanks !

 

[smoltz]

Did you just buy truck and it was like this? Or did it fail? If it failed did you have hvac/radio surround apart?

I had this problem on my LX450 which has same climate control unit. Issue was that temp sensor was unplugged. It's in the lower left corner of the HVAC unit if you're looking at it from front. It's not a very secure connection.

 

[LINUS]

Pull the HVAC unit, flip it around & change the switch on the back. There's only 1 so you can't mix up anything.

It makes it a manual unit instead of the auto-climate nonsense like a Audi has.

It may not solve the problem, but it won't hurt anything to try.

I've had both & a fulltime manual is plenty wonderful.

 

[GringoBob]

Did you just buy truck and it was like this? Or did it fail? If it failed did you have hvac/radio surround apart?

I had this problem on my LX450 which has same climate control unit. Issue was that temp sensor was unplugged. It's in the lower left corner of the HVAC unit if you're looking at it from front. It's not a very secure connection.

Thanks for the response Smoltz.

I bought this truck w/ no AC working and then the whole system failed (no heat, AC or fan.) I got it back working by cleaning/drying the Auto-HVAC computer circuit board with a electronics cleaner/dryer ...and I had the AC compressor rebuilt. And, oh yeah ...the aftermarket radio was pulled (...and I don't remember why) but my mechanic missed reconnecting the USB cable and I had to have him him pull the radio and connect it again. So ...maybe he disconnected the temp sensor and didn't reconnect it ??? ...or the problem was there before ???

I will have him check it out ! Thanks !

 

[GringoBob]

Pull the HVAC unit, flip it around & change the switch on the bac the unit and checking k. There's only 1 so you can't mix up anything.

It makes it a manual unit instead of the auto-climate nonsense like a Audi has.

It may not solve the problem, but it won't hurt anything to try.

I've had both & a fulltime manual is plenty wonderful.

Thanks Linus. We will be pulling the unit and checking that the temp sensor is connected. If that does not solve the problem, we will try using the manual setting on the back. In almost 50 years of driving I've never had an automatic climate control system ...and I don't think I need one now (especially after all the problems I've experienced with it!)

 

[excessive]

could also be the A/C amplifier gone bad,

 

[GringoBob]

could also be the A/C amplifier gone bad,

I hope not ...but if the other remedies don't work ...that's the next thing we will check. Thanks for pointing that out !