I drove to work this morning and the air conditioning worked fine, when I left work nothing but HOT air. I checked fuses, checked filter, refrigerant is full, the compressor is engaging, did diagnostic check on A/C and code "00" came up (which means normal)....


Any Ideas?


Thanks in advance.

 

The temp is set at 70...

 

Is it blowing hot on the passenger side too?

 

This happened to my mom's Buick
they checked everything that you did &
even flushed the A/C system and refilled all the fluids,
everything was fine but still didn't work.
then I took it somewhere else were there experts on A/C's,
they removed glove box
& behind it was an "switch" that controls an arm for hot & cold
(or something like that) & they flipped the switch on cold
now the passenger side is always on hot lol
Cost to much to fix for a 99 Buick
Hope this is not your problem

 

does both sides blow hot air or just one side? It could be the expansion valve causing your problems.

 

your servo motor is out.

 

Hot on both sides...

 

Is it easy to get to the servo motor? How can I check it?

 

https://www.clublexus.com/forums/gs-...ou-search.html

go down to interior, and DIY servo motor replacement.

check the FAQ next time you make a thread.