A/C light blinks 3 times and won't engage or turn on (2024)

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  • May 16, 2016
  • #1

Jetfumes

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Need some help. My battery died two days ago, and I replaced the battery, ever since my A/C won't engage or turn on. A/C was working before dead battery

I have a 00 GMC Yukon XL SLT with automatic climate control with rear climate control. I have removed all the HVAC &AC fuses and relay's to see if it resets itself. I have also tried holding the recirc and AC buttons at the same time to reset ambient temp.

Outside temp is 84F

Any thoughts?

  • May 16, 2016
  • #2

NathanJax

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Try this...

Press the AC & Recirculation buttons simultaneously with your index & middle finger. (The recirculation button is right above the AC button). This causes the an instant temperature update to your system and allow your AC to come on and stay on afterwards. My Chevy service rep. looked up the problem on his GM computer while I stood there, then he printed this solution off for me.

  • May 16, 2016
  • #3

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.

  • May 17, 2016
  • #4

Rivieraracing

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Great advice, will have to remember this for the future!

  • May 17, 2016
  • #5

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Jetfumes

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NathanJax I tried the Recirc and AC reset and that didn't work.

RedRocket I will give that try, and update the group.

I think this may be the trick since I had to change the battery and previous battery was dead.

Thanks again.

  • May 18, 2016
  • #6

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Jetfumes

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RedRocket your fix worked like a charm and saved lots of money. I appreciate it. Your tip probably should be in the tech info area.

  • May 18, 2016
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Rocket Man

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Jetfumes said:

RedRocket your fix worked like a charm and saved lots of money. I appreciate it. Your tip probably should be in the tech info area.

Done. I'm really glad that worked for you!

  • Jan 3, 2017
  • #8

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PeterD

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Jetfumes said:

Need some help. My battery died two days ago, and I replaced the battery, ever since my A/C won't engage or turn on. A/C was working before dead battery

I have a 00 GMC Yukon XL SLT with automatic climate control with rear climate control. I have removed all the HVAC &AC fuses and relay's to see if it resets itself. I have also tried holding the recirc and AC buttons at the same time to reset ambient temp.

Outside temp is 84F

Any thoughts?

I have a 2010 Yukon - same issue.
Had the ac all checked out - all good.
I warmed the vehicle up to about 7 celcius where we are now above the trip point (2c) where my ac would not work.
With vehicle turned off, I then removed the ambient temperature sensor from behind the grill.
All the computer remembers is the last reported temperature, so the ac comes on now any time I want it - mainly I needed it for de-fogging.
While I don't have the temperature indicated on the dash anymore, I do get my ac whenever I want.
In summer, I'll just put the temp sensor back in place.
Cheers,

  • Jan 4, 2017
  • #9

Rocket Man

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PeterD said:

I have a 2010 Yukon - same issue.
Had the ac all checked out - all good.
I warmed the vehicle up to about 7 celcius where we are now above the trip point (2c) where my ac would not work.
With vehicle turned off, I then removed the ambient temperature sensor from behind the grill.
All the computer remembers is the last reported temperature, so the ac comes on now any time I want it - mainly I needed it for de-fogging.
While I don't have the temperature indicated on the dash anymore, I do get my ac whenever I want.
In summer, I'll just put the temp sensor back in place.
Cheers,

Did you try my procedure first before going to that extreme?

  • May 27, 2019
  • #10

C

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Rocket Man said:

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.

Thank you so much for this. Fixe my problem! Lots of time spent searching before getting to here. Thanks again!

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A/C light blinks 3 times and won't engage or turn on (2024)

FAQs

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

Low Refrigerant Levels

Why is my AC light blinking 3 times but not? ›

One of the most common reasons for an air conditioner light blinking is low refrigerant levels. When the refrigerant level is low, it means that the system is not able to cool the air properly. This can be caused by a number of different things, such as a leak in the system, incorrect installation, or simply overuse.

Why is my A/C light blinking? ›

An air conditioning unit may give off a blinking light if it has poor air circulation. Air conditioners, particularly window air conditioners, require adequate air flow to function properly, and a blockage, dust buildup, or debris might be hindering this, prompting the air conditioner to give off a flashing light.

Why does my check engine light flash 3 times then stays on? ›

A flashing check engine light usually indicates a severe issue that requires immediate car repair. Issues that cause the engine lights to flash include an engine misfire, a loose fuel cap, and bad oxygen sensors. Unfortunately, the check engine light flashing is something a lot of drivers tend to ignore.

How do you reset an AC? ›

Finding Reset Button on AC Units

Look for the clearly labeled 'reset' button. Upon locating it, press the button for approximately three seconds and monitor the air conditioner. Verify if the AC starts operating immediately; if not, press the button again for an additional three seconds.

Why is the orange light blinking 3 times on my York air conditioner? ›

Blinking lights are usually a sign that something is wrong with your appliance. In the case of an air conditioner, it could be caused by a number of different things: a faulty capacitor, low refrigerant levels, or a clogged air filter. Of these three potential causes, a clogged air filter is the most common.

How do you reset a flashing thermostat? ›

It is most often the case that your indoor unit does not know there is a problem and keeps running. Occasionally, resetting the system will solve the problem. You can reset your thermostat system by turning the thermostat off, waiting thirty seconds, then turning it back on.

What causes lights to blink when air conditioner comes on? ›

Lights flicker when your AC turns on because electricity is pulled away from them momentarily to support the enormous power draw required to turn on your air conditioner. It's likely not a severe problem, and it's certainly not a spook or spirit trying to get your attention.

What is engine fault code 3? ›

0 – Fuel and air metering, and auxiliary emission controls. 1 – Fuel and air metering. 2 – Fuel and air metering (injector circuit) 3 – Ignition systems or misfires.

Why is my check engine light flashing and not starting? ›

The most common cause is any defects in the ignition system. Another popular culprit is a faulty fuel system. These may involve swapping out pricier parts such as fuel injectors. The third possible explanation for engine misfires is an internal engine problem.

What is a soft failure in a car? ›

Intermittent flashing of your check engine light occurs when your engine experiences what's called either an “intermittent failure” or “soft failure.” Soft failures are caused by engine problems that need certain conditions to appear. The most common example of an intermittent failure is that of broken wires.

Why is my AC light blinking and not turning on? ›

The most common issue that causes the AC not to work and the light to flash is due to the system being low on freon. It is possible the system is low on freon due to a leak.

How do I reset my AC relay? ›

Some air conditioning systems have a reset switch, which is a small, red button. Typically, the button will be on the outdoor unit. If you have a problem locating it on the outdoor unit, you may find relevant details on the equipment's manufacturer's manual. Press the red button for three seconds and release.

What does it mean when your battery blinks 3 times? ›

This is a standard safety feature in that batteries are designed to cut out in order to prevent overheating. Certain batteries will flash 3 times to indicate a short circuit.

What is error 3 in air conditioner? ›

The E3 error code indicates the unit has detected there is no refrigerant. The unit will require a repair service for refrigerant to be added, please visit Request a Repair page for further assistance.

Why is my Mitsubishi AC light blinking 3 times? ›

Mitsubishi Aircon Indoor Unit Blinking Light

For blinking twice, it could be faulty indoor thermistor, or both indoor thermistor and PCB. When the light is blinking three or four times, check the indoor fan motor and electronic control PCB if they are functioning normally.

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