LX Forums Forum banner

A/C Issue

6K views 4 replies 4 participants last post by  RDT 
#1 ·
Got in my car yesterday and turned on the A/C (90 degrees here!!), and cold air was coming out of the driver's side vents, and "cool" air was coming out of the other vents. I checked the temp setting (dual zone climate control) and even moved the passenger side up, then down to the coldest setting with no change. Anyone have any ideas?
 
#2 ·
You are low on refrigerant. The design of the evaporator core sends the liquid refrigerant through the drivers side of the core first, then passenger side. The low level of refrigerant means liquid refrigerant has made it to the drivers side, but has absorbed all it can and has turned back into a gas, which will not absorb heat (hence warm air on passenger side). When the charge amount is right, almost the entire evaporator is filled with liquid refrigerant, thereby absorbing heat and providing you with cold air on both sides. It keeps happening to me because I can't track down a VERY slow leak. Once I recharge, all is well again.
 
#3 ·
There are several blend-air and baffle doors that direct the air through the HVAC housing. They will from time to time get confused and need to relearn their position, or even break between the door and its actuator. The relearn can be initiated by removing the battery power for a bit. If you listen real close when the car is restarted you can hear the doors going back and forth as the computer relearns their position. There is a good description of how the HVAC system operates in the service manual.

Good luck.
 
#4 ·
This is the first thing I'd try, but the best way is to "recalibrate" the entire system of doors using a quality diagnostic scanner with this capability. I just did this on my 300C using my Autel MS906 and it helped somewhat, but I may have other problems. I'll do a complete check of system and a pressure check too. I also have another LX (Magnum) and will also use it for airflow comparison purposes. For sure the 300 doesn't work as good as my Jeep with the same dual zone system. Good to have another LX to check things with though.

When I had the front wheel wells out a while back, there was all kinds of leaves, pine needles and other stuff everywhere. Maybe some of this crap got into the system somewhere and is causing an obstruction and/or restriction. In any case, a little troubleshooting is in order for me.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top