Have a 1999 C4 - when I set the AC setting on Low I have plenty of cold air, however as soon as I try to make it a little less cold by moving up one notch I get hot air as if the heater is on - previously I'm quite certain that I was able to control the temperature of the cold air without going directly to hot air - any suggestions? Thank you in advance.

 

Something like that happened on my BMW when the ambient air temp sensor was damaged. Perhaps check that?

 

I'll take a look at the sensor - thanks for your input.

 

have the same issue with my 1999.....BUT my ambient air sensor, which i believe is mounted in the front of the car in the grille down low....seems to read OAT and display correctly on the dash.

would like to see if you have a fix for this.

 

I was just about to go see what my INDY shop had to say about it and it starts working flawlessly - will have to see how long this lasts. I'm not a fan of intermittent issues - OCD and all.....