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Ask Kevin Bourcier Your Own Question
Kevin Bourcier
Kevin Bourcier,
Category: Chevy
Satisfied Customers: 118
Experience:  Owner/Technician at Max Air Mobile
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Ac light flashes 3 times then blows hot air, the snowflake

Customer Question

ac light flashes 3 times then blows hot air
JA: Just to clarify, can you tell me which light it is? And does it blink first, then stay on steady?
Customer: the snowflake light yes the light blinks 3 times then goes off
JA: What is the model/year of your Chevy?
Customer: gmc 2001 yukon xl
JA: Are you fixing your Yukon XL yourself? What have you tried so far?
Customer: no the shop they replaced the whole system several times
JA: Anything else you want the mechanic to know before I connect you?
Customer: thats it
Submitted: 1 year ago.
Category: Chevy
Expert:  Kevin Bourcier replied 1 year ago.

hello I wil assist your with this . do you have access to a scanner ?

Customer: replied 1 year ago.
Expert:  Kevin Bourcier replied 1 year ago.

what do you have for DTC's ?

Expert:  Kevin Bourcier replied 1 year ago.

when the light is blinking if your raise the hood do you see that the compressor is NOT engaged ?

Customer: replied 1 year ago.
It is engaged
Expert:  Kevin Bourcier replied 1 year ago.

have you had the refrigerant charge level checked ? If the compressor is engaged and running at idle , you need to see about 15 to 30 PSI on the low side and 175 to 250 PSI on the High side gauges . The blinking light normally indicates a Low refrigerant charge due to a leak in the A/C system .

Expert:  Kevin Bourcier replied 1 year ago.

at an idle with the compressor engaged , is the Large Aluminum pipe at the passenger side firewall " Cpld " and wet ? ( sweating )

Expert:  Kevin Bourcier replied 1 year ago.

* Cold

Expert:  Kevin Bourcier replied 1 year ago.

the flashing light is telling you that you have DTC's you need to scan the HVAC to see what the code ( codes ) are .

Customer: replied 1 year ago.
u thinking there is a leak somewhere in the system
Expert:  Kevin Bourcier replied 1 year ago.

It is very likely , do you have rear A/C ?

Customer: replied 1 year ago.
I have rear AC
Expert:  Kevin Bourcier replied 1 year ago.

but I strongly suggest that you scan the HVAC . A good quality scan tool will tell you that you have a low charge problem . O common eak area is the lines going to the rear A/C Evaporator unit as they run under the vehicle and are aluminum and are exposed to the road spray / salt if you live in an area with a cold winter climate , etc .

Expert:  Kevin Bourcier replied 1 year ago.

you can also do a quick check by doing as I suggested . See if the large aluminum A/C pipe at the firewall ( passenger side ) is " COLD " . It should be very cold to touch and wet, sweating .

Customer: replied 1 year ago.
I live in Hou Tex it is hot as the Dickens on hot days it runs well for hours then blinks still blows but hot air then it might turn on or might not I will check
Expert:  Kevin Bourcier replied 1 year ago.

okay LOL . so no worries about cold winters and road salt . you most likely are low on refrigerant . you need to do some of these checks in order to get headed in the right direction to find the fault . Can you do any of the things I have suggested ?

Customer: replied 1 year ago.
I can
Expert:  Kevin Bourcier replied 1 year ago.

you can also have an intermitant electrical fault with the A/C pressure switch . YOU really need to scan the HVAC system . there WILL be diagnostic trouble codes stored .

Customer: replied 1 year ago.
How to scan the HVAC SYSTEM
Expert:  Kevin Bourcier replied 1 year ago.

a scan tool connects to the datalink connector ( DLC ) and should give you the option of what module to scan , eg , ECM ( engine ) BCM ( Body ) ABS ( braking ) , etc . The menu will include the HVAC module . If your scanner does not give you the option for HVAC then you will need to find a scanner that is a more professional grade that has that functionality .

Expert:  Kevin Bourcier replied 1 year ago.

how are you progressing with this sir ?

Expert:  Kevin Bourcier replied 1 year ago.

hello ?