I have a 2004 Highlander V6 AWD and the air conditioner seems to stick ON intermittently. After using the AC, I will turn it off via the pushbutton, the little green light goes out, but the AC stays on.
At other times, I push the button from ON to OFF, and it actually goes off.
What might cause this problem? I certainly don't want to have the AC running anytime the fan is on, as it will cause wear & tear and lower gas mileage.
Thanks!
BC
How did you verify that the AC was in fact on when you selected off? Did you visually see the AC clutch engaged? Or, just the air blowing from the ducts remained cold for a time? It might be a faulty AC clutch relay. If that is functioning, it may be the button itself or the wiring.
I did not see the AC clutch engaged. Don't know where it is.
I began to notice that when I would switch off the AC to just get outside air, that the air blowing from the vents remained cold for the remainder of my trip. I use the Defrost setting to blow the cold air across the inside of the windshield, and I began to notice that the air stayed cold enough to cause condensation on the outside of the windshield.
While at a stoplight, I also noticed that when I would turn on the fan, I could hear the engine load as if the AC was on, though the switch showed it was off.
At other times, the AC went off, the air from the vents warmed up, the condensation stopped.
What's the best way to determine if it's the relay or the button? Is the relay more accessible than the the button (which I assume would mean dismantling the dashboard)?
Thanks again! BC
The defrost setting keeps the A/C on, to dry the air. When the air goes against cold coils, water condenses, leaving the air dry. If there is little moisture in the air, the windshield doesn't fog up. The fog is water vapor after all.
The A/C works not only in the A/C position, but in the defog position as well (plus any positions like floor/defog).
What was the position of the switch when the A/C wasn't working?
Determining whether or not there is a problem, first.
Jeff
Exactly like Jeff mentioned in his post. I think your system is working normally. By selecting defrost the AC compressor will run and if you have a cold temp selected, you are running the system as if the AC is selected, the exception being that the air is ducted differently. In addition, if you have the system selected to recirculate the inside air, as for max AC, that function should revert automatically to outside air when defrost is selected. You might be able to learn more about the system for your particular vehicle in the owners manual.
I hadn't thought about the defrost position activating the AC even though the switch was off. Will test!
Thanks.
BC
Will check further to see if it's really stuck on. Thank you.
BC
Well, y'all were correct. I mistook the AC/defrost setting for the AC being stuck on. I have had 5 Toyotas and didn't know about this! And yes, it is in the manual.
I'm embarrassed, but less so than if I'd taken it to the shop. Thanks for the help.
BC
Probably left your pocket book intact too. Sometimes the dealer is helpful when explained things but other times, at least the dealer(s) I have seen, they all want $80-90 for a diagnostic just to put ANY thought or research into an issue that really just 2 min of interaction and demonstration would solve.
Glad it's all settled!
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