A/C light blinks 3 times and won't engage or turn on

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Sean James

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Wow, who would have thought? Thanks Rocket Man, I knew about the power to ground discharge for other module issues, but not for A/C. Most people would automatically think failure in the A/C system, which is always a weak link in any vehicle. Good to know info. Thanks!
 

Apryl Blakney

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We have a 2010 yukon. Ac is warm and heat isnt super hot either. AC button blinks 3 times. Tried the fuse removal trick 2x. Didnt work. Tried holding AC and recirculate together. nothing. Tried adding coolant to the system, it says the pressure is good. Help. This only has 70k miles and has been in Minnesota with rarely used AC. Can it need a new compressor?
 

Rocket Man

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We have a 2010 yukon. Ac is warm and heat isnt super hot either. AC button blinks 3 times. Tried the fuse removal trick 2x. Didnt work. Tried holding AC and recirculate together. nothing. Tried adding coolant to the system, it says the pressure is good. Help. This only has 70k miles and has been in Minnesota with rarely used AC. Can it need a new compressor?
Are you sure you have it on the correct setting? It can’t be set to any of the defrost settings, it must be set to blow through the lower or front of the dash vents FYI.
 

eholl

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Hi... sorry to hi-jack your thread, but I'm having an issue with my AC on an '09 Yukon XL SLT... I push the ice button and it blinks 3 times and the AC does not come on.

The air blows, but not cold. I tried a couple of things already.

1. Replaced the sensor on the compressor (but it didn't come with an o-ring so I left the old one on.)
2. Tried the manual reset by pressing the ICE and recirculate button (but I didn't know how long to hold them in so I held them for 10 seconds.)
3. Undid the power supply from the battery. Waited 10 minutes, discharged the line by touching to ground. Restarted car, ran for 5 minutes and turned on air. No luck.

Question -

Will the AC light blink 3 times if it is simply low on freon? If so, I'll try adding some.


I've already resigned myself to taking it into the shop, but wondered if there were any other 'common' things to try on my own before hand.

Any advice is greatly appreciated.
 

Lamaf

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Hi, I have a tahoe Hybrid 2011 with the same symptoms, I tried this
The 3 blinks usually means something isn't in the correct position for the A/C to operate- either the mode control is in the wrong position (a/c doesn't work in defrost mode, etc.) or the compressor won't turn on for some reason. There is another reset procedure other than the one Nathanjax mentioned- first start it up and set all hvac controls to off, then shut off the engine, disconnect the positive battery cable, wait 10 minutes, then before reconnecting it touch it to the negative battery post for a complete discharge of the system. Reconnect the cable and start up the engine but don't touch the hvac controls for at least 5 minutes during which time all the actuators (mode, blend, recirc) recalibrate. After 5-10 minutes, try the a/c. This is the only thing that has worked for me in the past after I changed out parts of the system.
But it did not work, some details I would like to confirm:
- when I restart the engine the HVAC is on, is it OK or should I turn it off for the 5 minutes recalibration ? ( I turned it off before disconnecting the battery)
- When I restart the engine, it does not turn for 5 minutes but switches to the electrical mode and the gas engine stops. Is this an issue ?

What I did :
1- Turn the engine on
2- turn the HVAC off
3- Turn the engine off
4- Disconnect the battery positive cable
5- wait 10 minutes
6- Make the positive cable touch the negative cable
7- Reconnect the battery
8- Start the engine (the HVAC is on and the dashboard says 13 degrees when it is 43 outside)
9- Wait 5 minutes
10- push the A/C button: the A/C light blinks
11- Press A/C and recirculation : dashboard temperature is now OK indicating 43 but AC is still blinking

The AC was working fine but my battery was down, I changed it and now it does not work

Thank you for your help
 

alpha_omega

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Hi, I have a tahoe Hybrid 2011 with the same symptoms, I tried this

But it did not work, some details I would like to confirm:
- when I restart the engine the HVAC is on, is it OK or should I turn it off for the 5 minutes recalibration ? ( I turned it off before disconnecting the battery)
- When I restart the engine, it does not turn for 5 minutes but switches to the electrical mode and the gas engine stops. Is this an issue ?

What I did :
1- Turn the engine on
2- turn the HVAC off
3- Turn the engine off
4- Disconnect the battery positive cable
5- wait 10 minutes
6- Make the positive cable touch the negative cable
7- Reconnect the battery
8- Start the engine (the HVAC is on and the dashboard says 13 degrees when it is 43 outside)
9- Wait 5 minutes
10- push the A/C button: the A/C light blinks
11- Press A/C and recirculation : dashboard temperature is now OK indicating 43 but AC is still blinking

The AC was working fine but my battery was down, I changed it and now it does not work

Thank you for your help
Did you ever get this problem with your a/c figured out?
 

Jasonr3085

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The 3 blinks usually means something isn't in the correct position for the A/C to operate- either the mode control is in the wrong position (a/c doesn't work in defrost mode, etc.) or the compressor won't turn on for some reason. There is another reset procedure other than the one Nathanjax mentioned- first start it up and set all hvac controls to off, then shut off the engine, disconnect the positive battery cable, wait 10 minutes, then before reconnecting it touch it to the negative battery post for a complete discharge of the system. Reconnect the cable and start up the engine but don't touch the hvac controls for at least 5 minutes during which time all the actuators (mode, blend, recirc) recalibrate. After 5-10 minutes, try the a/c. This is the only thing that has worked for me in the past after I changed out parts of the
 

Jasonr3085

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The 3 blinks usually means something isn't in the correct position for the A/C to operate- either the mode control is in the wrong position (a/c doesn't work in defrost mode, etc.) or the compressor won't turn on for some reason. There is another reset procedure other than the one Nathanjax mentioned- first start it up and set all hvac controls to off, then shut off the engine, disconnect the positive battery cable, wait 10 minutes, then before reconnecting it touch it to the negative battery post for a complete discharge of the system. Reconnect the cable and start up the engine but don't touch the hvac controls for at least 5 minutes during which time all the actuators (mode, blend, recirc) recalibrate. After 5-10 minutes, try the a/c. This is the only thing that has worked for me in the past after I changed out parts of the system.
Life saver bro! Batter died two days ago and just noticed today that my ac wasn’t throwing cold air looked it up and this came out thanks bro saved me some money!
 

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