Hey all,

I recently fixed a vacuum leak that was not allowing my blend doors to actuate and was defaulting my air to a mixed hot and air mixture.
Now the air controls work perfect, and I have no HVAC codes.

Beware of the old fragile nylon vacuum lines yall!!!

However the issue still remains when I try to turn on the AC by pushing the button on the center console, the AC light will flash for about 6 times, and then turn off, and the air does not get colder.
Sometimes when I press the AC button, the light will turn on for about 4 seconds and then just turn off and the air does not get colder as well.

Any help is appreciated please

 

Put a set a gauges on the high/low side, and follow the service manual.. The A/C troubleshooting is pretty good in the service manual.

 

Your AC system is probably low on freon, you should also have a leak test done.

 

Any trouble codes ??...you can try swapping the AC Clutch Relay with another relay like the horn...if you have a test light you can check the relay...with key on engine off you can even try jumping the load side of the relay (30 and 87) and see if the clutch engages...there are inputs that can keep the AC from coming on such as the AC Pressure Sensor and Ambient Temp Sensor.

 

Update: With a proper freon recharge, the system works properly now.

Hopefully this helps someone in the future:
If you press the AC button and the compressor does not activate, AND you checked everything else, the system is probably just low on Freon. I recommend getting your system charged by a professional, as the system can easily be recharged improperly if the system is not fully understood.

Thanks all, time to enjoy cruising with the windows up and cold air blasting my face!

 

If it needed a recharge you evidently have a leak…I’d get that fixed and then recharge.

 

Maybe.. But the previous owner said, his AC never worked. So it’s now that it’s recharged, will monitor for leaks and loss of cooling. Do you have recommendations for how to check for freon leaks?

 

Well if the refrigerant you used has a dye you use a UV light…you can also use an ultrasonic or a halogen leak detector…a thermal imaging camera is another method.

 

I did just read about the UV light detection method. I have a UV light laying around, I’ll try this tonight. Another silly question: When I got the car, it never had a cap for the low-point shrader valve. Could this be a culprit of a leak? I’m going to buy one today anyways.

 

The cap is just there to prevent dirt and water from entering so it will not stop the leak if the Schrader were leaking.

 

Copy. Will continue to monitor for leaks. But for now, thanks for all the help and knowledge

 

There are a few common ways to leak check. If you lose your cooling in a week or 2, it should be relatively easy to find. If it is a slower leak, it may be more challenging. In no particular order:

1. Refrigerant dye with a black light and glasses. You run the system with normal driving. Check every connection. Check the condensate water dripping under the car. Check it a few times over the next days.
2. A thorough visual inspection of every connection joint, the joints on the compressor body, the manifold hose connection plus relief valve and the control valve all located at the back of the compressor, and the clutch/pulley looking for dirt clinging to oily residue.
3. Soapy water sprayed on every connection joint as in method 2. If you have a nice warm day and the engine compartment is hot, you may have 90psi or more pressure in the system.
4. Buy, rent, or borrow a refrigerant leak detector/sniffer that detects R134a. Sniff everything from method 2. With the a/c running, put the sniffer probe in the center air vent too to sniff for an evaporator.

If any or all these methods are inconclusive and your system runs well all Summer but then is low again the next Spring, you may have a “phantom leak” where refrigerant is lost over the cold weather as the joints and connection elastomers change with the cold.

 

So the shop you took it to just added refrigerant, they actually did not do a full service?...which is what they should have done. That process would have checked for leaks.

 

Lucky, I did not specifically state that I took this car to the shop for the AC. I actually just called my buddy who’s a mechanic on the phone and he guided me how to do it properly. But he did not mention a leak though

 

Actually, according to GM they consider the cap the primary seal. Ludicrous, obviously, but the proper cap does help.
The Schrader valves are somewhat common leak points in the system, and can be problematic to diagnose, since they are often connected to gages during vacuum application.

 

I guess this is what led to my assumption that you took it somewhere to be serviced. So it's blowing cold, so you probably don't care, but given that the A/C never worked for the previous owner, how do you know your system is "properly" serviced?

 

My buddy who is a mechanic was guiding me through the process doing it at home. Also for double verification, I took it in to a shop and they said it’s all good