Replacing Climate Control Head Unit

[gzhao888]

I have a 2003 Avalon XLS which has some A/C problem. The A/C blows warm air even at 65F and blow some cool air but not cold enough when set at COLD. The car was taken to a shop which said that the climate control head unit is broken and needs to be replaced and it costs near $1000 for the part alone. Based on the part number given by the shop, I find a similar but not identical unit on ebay for around $50. So I am intended to replace it myself. I am a newbie about auto repair but I am willing to try. Is anyone on this board done something similar or have instructions on how to disassemble the head unit which is the wood panel with digital display and probably some internal component. Any information will be greatly appreciated.

[KoG506]

Originally Posted by gzhao888

I have a 2003 Avalon XLS which has some A/C problem. The A/C blows warm air even at 65F and blow some cool air but not cold enough when set at COLD. The car was taken to a shop which said that the climate control head unit is broken and needs to be replaced and it costs near $1000 for the part alone. Based on the part number given by the shop, I find a similar but not identical unit on ebay for around $50. So I am intended to replace it myself. I am a newbie about auto repair but I am willing to try. Is anyone on this board done something similar or have instructions on how to disassemble the head unit which is the wood panel with digital display and probably some internal component. Any information will be greatly appreciated.

First of all,

I personally would check for A/C leaks, add more FREON in, ask other shops/mechanic, and see if there is a difference and opinions. I don't think the climate control could be broken, it just seems waaaayy to rare for that unit to break.

The $50 unit i believe are not digital? you have to buy an identical one because of digital wiring not compatible with manual unit and vice versa. Good luck and keep this posted!

[buchaja]

Listen to Ko and keep researching this problem.

I'm not an auto tech, but I have a 2003 xls too. Sounds like your describing a temperature problem and not a controler problem.

Get a qualified AC technician to diagnose it, or add some juice yourself (freon, refrigerant, R14 - or whatever it is these days) and see if it improves. Then look for leaks and check that the compressor is cycling.

Good luck.

[gzhao888]

Thanks for the comments. I have checked Freon on LOW side, which is about 80psi when engine is either off or on. Also the compressor is engaging when A/C is on. I have compared the LOW side pressure to another car, 2002 highlander which also reads at about 80 psi. So Freon seems OK. Last summer, the A/C works very well. But last Oct, I took the car to a dealer for a Steering Wheel Column recall then suddenly I have this problem. Not sure whether this is related but I suspect the cabin temperature sensor may be damaged when the car was being serviced which causes the control does not know the inside temperature and causes blowing of hot air even at the setting of 65F (outside temperature was at 90F). I was told that the cabin temperature sensor is at the location which is a few inches directly below the ignition. By removing a square shaped cover on the ignition, I see a white plastic tubing (about 3/4 inch in diameter) connected to an angle shaped plastic device on the end, Anyone know hos the sensor works and how to remove and replace the sensor?