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AC not cold and excessive moisture/water under the car

Posted: Wed Jun 09, 2021 6:45 pm
by 2MD
2008 Chevy Trailblazer owner. AC works, but hardly cold. The compressor clutch is engaged and good, and the gauge I purchased shows refrigerant level being good as well. The one thing I have noticed is that when the AC running (and the car is parked), there is excessive amount of moisture buildup around the accumulator. I mean, like water starts running under the car onto the ground like there is an open faucet there... i mean i can probably bottle the water and sell it !!!! Anyway, I don't mind changing parts one by one (starting form the cheapest and easiest) until the issue is fixed, but correct me if I am wrong, there are no parts in the system that can be changed without having to capture the refrigerant first, correct? I am not willing to release refrigerant into the atmosphere, in which case I guess i have to go to a shop when i am suspecting min $800 . . I still like to be able to isolate the issue and any suggestions is appreciated. Thanks..

Re: AC not cold and excessive moisture/water under the car

Posted: Wed Jun 09, 2021 8:39 pm
by tbirdtbird
Seems to be a restriction at the accumulator.

"changing parts one by one (starting from the cheapest and easiest) " won't be easy and not cheap

"there are no parts in the system that can be changed without having to capture the refrigerant first, correct?"
Correct

You cannot determine proper refrigerant level from pressures

You will prolly have to take it to a shop

Re: AC not cold and excessive moisture/water under the car

Posted: Wed Jun 09, 2021 9:50 pm
by jluke42
Before carrying it to a shop, check the operation of your temperature blend door actuator. If your pressures are correct, the compressor is staying engaged and it is producing that much condensate, the refrigeration portion of the system is probably OK. If the actuator is stuck on "heat", then the cold air off the evaporator is passing thru the hot heater core and being reheated. There are several ways to easily check its operation. One, turn off "A/C" and turn to "Heat", see if you can change the temperature of the discharge air. If it is operating correctly, you will be able to change temperature.
Second way is to clamp off the heater hoses with the A/C on and see if it changes temperature of discharge air. A third way is to turn on A/C immediately after a cold engine start (before heater core has time to get hot) and see if that changes the discharge temperature.

I feel you have a reheat issue with the blend actuator probably being the culprit. I have seen it happen several times on my own and my friend's vehicles.

Re: AC not cold and excessive moisture/water under the car

Posted: Fri Jun 11, 2021 9:10 am
by JohnHere
Your Trailblazer is around 13 years old. If the A/C system has never been serviced, it's probable that the insufficient cooling issue you're experiencing is due to a low refrigerant charge.

As already mentioned, you can't determine the refrigerant amount by pressures. What's needed is to recover the existing charge and weigh it to determine how much is in the system now. I would guess it's low. Then evacuate and recharge to specifications. At the same time, installing some UV dye for purposes of leak-checking is also a good idea.

Chances are, you don't have the know-how and equipment to service it. So I suggest taking the vehicle to a professional A/C shop, also mentioned earlier, to have the work done. That service won't cost anywhere near $800 unless some other major problems need to be addressed. Blindly replacing components not only is expensive but also ill advised because doing so might not solve the problem anyway.

The specs for your vehicle are as follows: Without rear A/C, 30.4 ounces of R-134a and 8 ounces of PAG-46 oil. With rear A/C, 42.5 ounces of R-134a and 8.5 ounces of PAG-46.

Re: AC not cold and excessive moisture/water under the car

Posted: Fri Jun 25, 2021 4:50 am
by Dougflas
jluke42 wrote: Wed Jun 09, 2021 9:50 pm Before carrying it to a shop, check the operation of your temperature blend door actuator. If your pressures are correct, the compressor is staying engaged and it is producing that much condensate, the refrigeration portion of the system is probably OK. If the actuator is stuck on "heat", then the cold air off the evaporator is passing thru the hot heater core and being reheated. There are several ways to easily check its operation. One, turn off "A/C" and turn to "Heat", see if you can change the temperature of the discharge air. If it is operating correctly, you will be able to change temperature.
Second way is to clamp off the heater hoses with the A/C on and see if it changes temperature of discharge air. A third way is to turn on A/C immediately after a cold engine start (before heater core has time to get hot) and see if that changes the discharge temperature.

I feel you have a reheat issue with the blend actuator probably being the culprit. I have seen it happen several times on my own and my friend's vehicles.
yep. If there is condensate on the ground, it is reasonable to think the refrigeration system is ok. This is exactly where I would go first.

Re: AC not cold and excessive moisture/water under the car

Posted: Sat Jun 26, 2021 1:34 pm
by DetroitAC
I agree with jluke42, this is good advice