HELP! 2005 Toyota Highlander Passenger side A/C vents blow cold air Driver side Hot - no dual temp

History - So my A/C was going out about 6 months ago. It would come in and out with cold air until eventually it just stopped all cold air and was only hot. Then the control knobs broke. I took it in and they told me I had to replace the control unit and that would fix all the issues. Well I got it back and the A/C was still blowing hot air (even though the knobs were now working). So I took it back in and they said they couldn’t find anything wrong and it must be this hairline crack that was leaking freon. they said they couldn’t find the crack but loaded it up with freon and said i would have to ‘wait it out’ could be years could be a few weeks, they just didn’t know. well, it worked for awhile but here i am in 102 degree heat and when I turn on the A/C in the really hot car the passenger side quickly blows cold air and the driver side takes about 20 minutes before it finally gets cold. What gives? I do not have dual temperature controls.

If it’s just one side…then it’s NOT the AC…Sounds like a blending door or the system that controls it.

Find another mechanic…these fools have no idea what they’re doing.

Depends on the shape of your evaporator and the way the air flows, but when one side of the car is colder than the other, it could mean that the freon is low again. When you are low on freon, a weak stream of freon comes spitting in to one end of the evaporator, and only that end of the evaporator gets cold, so only that side of the car gets cold air. If this theory is right, soon you will have so little freon that the system won’t have enough pressure for the compressor to engage, then you will have no cold air at all.

Freon leaks are not hard to find. You need a new shop.