Hey everyone. I was working on my car today and was messing with the rear AC on my UL. I noticed not a lot if cool air coming out of the upper door vents. It blows air, it's not cold or hot, kinda in between when set to max cold. Any ideas what could cause this? I scanned the car and there are no codes. Front seat AC is perfect. Are there two separate AC units?

 

There are two ac coils when freon is slightly low these vents blow cool but not cold mine was warmer on the top passenger vent. Also if you turn on the ac with all vents on low in a quiet stop like at a light you may hear a rushing sound from the drivers side in back of the dash. The rear ac is at the very tail of the system and if slightly low the effect will be less cooling from the upper vents because that is where the system suffers when slightly low. Many say no freon should leak over time and if it does you have a leak that has to be located and fixed. I disagree and believe on some cars a very slight amount will come out over many years and many miles. If the leak is extremely slight it could be a lot of work and expense to fix what can be toped off once in a great while for a few bucks (you do not want to create other problems in the process when trying to locate and repair a miniscule leak) Have a pro add some freon and you should be good for a long time to come.



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Thanks for your reply. I agree with you, my car is 11 years old and has 150k miles, not surprised if over time the freon has gotten low. There could be a leak but I am not stressing about it. The rear air isn't something I use that frequently so I may wait to get it looked at. I guess you would't recommend adding freon myself?
Thanks so much

 

thankx for the idea