Unable to turn 'off' air conditioner?

I'm not sure which button you're saying remains on; you'll need to tell me which one it is. But:

Typically, either the fresh air or the recirc indicator will stay on to ind icate the position of the fresh/recirc door at any given time. If fresh ai r is indicated, the air will come out of the vents when the car is moving d ue to the pressure of the outside air against the base of the windshield wh ere the air inlet is located. To stop this, switch to recirc, and that wil l block outside air.

Any of the bottom buttons - ie the face button or face / feet button.

Hmm.. I'll try that. But air comes out even when sitting still :)

Well, that's odd unless it's *very* windy. Maybe the fan is still running.

The blower switch provides ground to both the fan and the relay for the pow er side of the fan. So the only thing I can see that would be a single pro blem that would make the fan continue running would be a shorted blower swi tch. Maybe try wiggling the blower knob side to side, up and down, in and out, etc. to see if there's a change.

Try pushing on the button marked "AC."

The A/C button switches off when I switch the knob to 0, and it becomes inactive (I can't turn it on or off).

Ok - I take that back - air isn't coming out (at least noticable air) when I'm not moving... but I find it odd it's either cool or hot air regardless of outside temperature, and it's dependant on whether the control is on cool or hot?

On Sat, 06 Sep 2014 05:29:19 -0700, Evan Platt wrote in

You mean the fan speed "knob"? If so, you are shutting the fan and that *should* shut the A/C off.

Is the compressor running when the a/c switches are off?. Maybe the clutch is stuck. It's pretty easy to tell.

Have you read your owner's manual so you know how the system is supposed to work? I am guessing not by your comment above.

Used car. Didn't come with an owners manual.

I googled and found one online. I'll read through the section on air conditioning.

Sounds normal then. The temperature control knob adjusts the position of d oors within the heater box to regulate the amount of air passing over the h eater core. Hence, adjusting this knob will adjust the vent temp even if o nly the smallest amount of air is flowing.

It is always annoying when people don't keep the owners manual and provide it when they sell a car. I am glad you found one. Knowing how the system is supposed to work is the first step to knowing whether it is working correctly or malfunctioning.

Good luck!