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i have a 2004 toyota highlander. when i have my climate control on blue, the coldest, warm air will sometimes blow out of the vents. also if i turn on the ac, warm air also blows out of the vents. any help would be appreciated

There are several things that it could be, but the most likely is that you have a small leak and are low on R-134.

If the system uses a blend door there is most likely a problem with it. I have this system in my Toyota Supra. This door regulates the amount of vent air passing through the heater core. When the temp control is all the way on cold, that door should be completely shut to the heater core. I believe the dashboard will have to be partially taken apart to reach it and determine the problem. Not a quick fix by any means.

However, my old Toyota Pick-up used a heater valve on the firewall to regulate the amount of coolant running to the heater core that was in-line with the vent system, and had no blend door. If your system is like that, then the heater valve is most likely the problem, and should be completely shut when the temperature control is on cold. Be careful, tho. My Supra also has a coolant valve, but it will only open fully or close fully. The pick-up’s valve allowed for partially opening to control the temperature.

I’m with Tardis on this one. This would not be abnormal for a 5 year old car. The leak will need to be identified and repaired and the system recharged. Normal work for any shop that services AC systems.

thank you for your response

thank you for your response

It blows warm air SOMETIMES when the control is in the blue area. It is warmer than expected with the AC off, correct? I am going with a blend door or heater valve. Give more detail about what times SOMETIMES is.

when i’m driving my car somedays or times cool air will blow out of vents. somedays or times warm air blows out of vents even in the ac mode. thank you for your response also