Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

Air Conditioning Problem, 2002 Trailblazer

27K views 23 replies 6 participants last post by  sn8bite 
#1 ·
When I turn my air conditioning on it blows cold for about a minute or two and then the air starts to turn warmer. I am having trouble pin pointing the problem. Anyone ever hear of this before or have any suggestions?
 
#2 ·
Both sides, driver's and passenger's?

How's the temperature of the receiver/drier, the silver canister on the passenger's side of the engine compartment on the firewall?

Is the compressor clutch still engaged?

Any debris clogging the fins of the condenser, the hot part of the AC system sitting in front of the radiator?

Any AC professional taken a look at the high and low side pressures with their gauges?
 
#6 ·
You need a better mechanic, then.

There should be no reason (unless you have a physical disability) that you can't get the answers to my questions. Is there?

How do you think Internet forum troubleshooting works anyway? You ask for help. Experienced people ask for data. You provide it. We guess (without being able to lay hands on the vehicle) what the problem might be, usually in order of probabilities. You take that guess and turn it into action by replacing parts and making more observations. If we ask you to get data like the voltage on a particular wire, you pull out a voltmeter and measure it.

It sounds like what you're asking us to do is unreasonable. If you already took it to a mechanic, are you saying you're going to take a list of our guesses back to the same mechanic to see if we can educate him as to the list of possible failures in an automotive AC system?

Volunteers here would love to help. But help us help you by engaging in the give-and-take process, please. :yes:
 
#8 ·
Just feel it. It should be wet from condensing moisture from the air like a cold soda can, and feel just above ice cold.

In a minute, as your interior air starts to get warm, see if the AC clutch is STILL engaged as expected and if the receiver/drier is as cold as before.

If the clutch is engaged, the compressor is spinning, and the receiver/drier starts to warm up to match the interior air temp, then freon charge would be my first guess. Get an AC professional instead of your original mechanic.
 
#10 ·
Either a failing low pressure cycling switch, mounted on the side of the receiver/drier, or low freon pressure. Your mechanic couldn't troubleshoot this? Just take it to an AC professional, since you might be wasting your money changing the low pressure switch. The function of the switch is to protect the compressor against fatally damaging itself if the freon is leaking out. A compressor cannot safely be allowed (or forced) to run while it's partially or fully discharged.
 
#11 ·
A/C trouble - 02 Envoy



I've been lurking in the background and following several A/C threads on this topic. My climate control A/C has been running fine for a short period and then shutting down after the engine gets hot. Following the recommendation on another thread, I was tapping the low pressure switch and it flipped the compressor back on...for a while. Seems likely to be the culprit in my case, so I will order a part tomorrow and see what happens.
I hope I didn't do the "Hijack" thing by jumping in.
Thanks, :tiphat
 
#15 ·
A/C Clutch coil. Which, from what Ive heard, if it goes bad the whole compressor must be replaced as a unit.

Do you have the digital HVAC display? If so, does your outside temperature read correct?

If the ambient temperature sensor is bad, it will prevent the compressor from working properly. If you do not have the digital HVAC, then ignore the last sentence.
 
#17 ·
Turns out to be the magnetic clutch in my case. I'm in over my head at this point:confused:, so my local A/C man is doing the repair.
$475 for the job.:worried:
Figured that it was the coil. Some other member mentioned it and it made sense.

$475 is not bad in a/c pricing terms!
 
#18 ·
I do not have the digital hvac display and i don't think its the compressor clutch because it actually works for the first minute and then completely stops spinning. There is something thats making the compressor clutch turn off, I just can't figure out what it is.
 
#22 ·
Then, next most likely possible issue, assuming you have the correct charge of 134a:

sounds to me like the clutch coil is going bad.when it shuts off wiggle the wiring harness and see if it comes back on.if it does check the plug for a broken or loose connector.
 
#23 ·
Where is the location of the low pressure switch?

My 02 Envoy's a/c is acting similarly, below 75 degrees the a/c works fine though not as cold, past 75 degrees, it's warm. :bonk:

I've already put in a can of r134a, it's gotten better but not as it once was.
 
#24 ·
get a gauge and check the pressure in the system while running.also check to see if the compressor is turning on and off(cycling) often.if pressure is low put more freeon in,preferably with a leak detector.be sure not to over fill the system,that will cause the compressor to cycle to protect itself form over pressurising.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top