How to decouple A/C and Recirculation from Defrost on a 2007 Toyota Corolla


This is a non-destructive method for preventing the A/C from turning on and recirculation from turning off when using the defroster.


Step 1)

Remove the shift knob and shifter plate.

The knob just unscrews CCW and the trim pops off if you pull from the back. Disconnect the cables on the cigarette lighter.

Step 2)

Remove the fan speed dial.

Just pull it off and remove the screw beneath it.

Step 3)

Remove the center console.

I found this easiest by following Dante Cordova’s suggestion of pulling with constant force from inside the fan knob opening. This was difficult because I didn’t want to break anything, but it eventually came out since there are only clips holding it in. Dave’s instructions can be found here:

Step 4)

Remove the A/C and Recirculation switch unit from the heating knob unit.

Turn the settings knob away from any defrost setting.

There are two clips that prevent the A/C and Recirculation switch unit from sliding forward on the heating control unit. The clips are in red and the rails are yellow. This picture is after the removal, but placed back on slightly ajar so I could highlight the key elements.

You need a small, but long flat head screwdriver or some other long prying device. I used a 4 inch electronics screw driver. Gently pry a clip up with the screwdriver until it pops out of the hole then repeat for the other. Once this is done you can slide the switch unit forward, remove the plug at the back of the switch unit if it can’t slid all the way forward.

*NOTE:* Be careful not to twist the heating knob unit around too much if you decide to take it out for some unknown reason. They knobs are connected by push-pull cables, and a crimp in a cable will prevent it from working properly.

Step 5)

Push the 2 rotors to the left. Alternatively you can turn the settings knob to defrost and the just nudge the rotors a bit further to the left to prevent them from interfering with the switch unit when you reinstall it. They move easily, so no force should be required.

Just slide the switch unit back on until you hear a click when the clips spring back into place and you’re done.

Why it works:

There are 2 levers on the bottom of the switch unit. When lever 1 is pushed to the left it engages the A/C, and when lever 2 is pushed to the left, it disengages the recirculation button. By moving the rotors to the left in step 5, they are moved to the opposite side of the levers and so they push nothing. Problem solved.

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