I tried resetting the A/C, but it didn't work for me - the rear defrost light never gave me 3 blinks confirmation. I pressed and held the recirc and front defrost buttons, held for 3 seconds after turning to ACC, then continued to hold for 3 seconds after turning ignition to ON, but no blinking light. What am I doing wrong?

its just the one on the left and the recirculate

right, I'm pressing and holding the left defrost and recirc buttons, but the right defrost button is supposed to blink 3 times to confirm that it worked, and mine's not doing that.

in what circumstances does the a/c requires to be reset?

^+1 just wondering

^Beats me, didnt even know we could do that :lol:

Easier to just copy/paste this:

AC NOT COOL (AFTER 9/11/03 PRODUCTION)
Applicable Models
Model Starting S/N Ending S/N
2004 RX8 40118171 ********

Some customers may complain of lack of AC cooling from the vents. This may be caused by the intake air selector (recirculate / fresh) in the "FRESH" mode. Cooling the interior of the vehicle may take longer if the air intake selector is in the "FRESH" mode. Maximum cooling is achieved when the intake air selector mode is in the "RECIRC" position. The AC amplifier can be programmed to automatically default to "RECIRC" mode when the following conditions are met:
1. Ambient air temperature is 68 deg. F or higher.
2. HVAC control mode is in "FACE" mode.
3. HVAC temperature is in maximum cool setting. Customers with this concern should have their vehicle repaired using the repair procedure. NOTE: Vehicles produced before 9/11/2003 are not programmable and should have the AC amp replaced per Service Bulletin # 07-002/04

1. Verify concern.
2. Verify ignition switch is in OFF position.
3. Press and hold the front defrost and air intake selector buttons simultaneously.
4. Turn the ignition key to the "ACC" position for 3 seconds. (Continue to hold the buttons down from step #3.)
5. Turn the ignition key to the "ON" position for 3 seconds. (Continue to hold the buttons down from step #4.)
6. Successful programming will be confirmed by the rear defrost indicator light flashing 3 times. NOTE: If vehicle's battery dies or cables are removed, the programming will not be retained and must be performed again.

oh i see so if its automaticall on recirc then im good to go?

His rear defrost light probably isn't blinking while performing the reset because the AC amp is already defaulted to "RECIRC"

right, I'm pressing and holding the left defrost and recirc buttons.....

no it's the recirc button the lower left one not both

oh i see so if its automaticall on recirc then im good to go?

Remember, that is an old bulletin. At some point after that, the amplifier was changed, iirc. So that procedure may only apply to 2004,2005 or so, but I can't say for sure. Mine is 2004 and needs that procedure, which I have renamed the "Set AC to secret, non-suck mode" procedure.