AC issues continue.
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AudiWorld Super User
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AC issues continue.
My AC still cycles off at idle. I have no done the AC troubleshoot where you warm car up, set temp to low, etc. I know the outcome. The AC will continue to turn itself on and off every 30seconds or so.
I tried something else the other day.
When sitting at a stoplight I kept the engine revved to 20000-2500 rpms. AC stayed on with no issues.
When sitting at a stoplight and letting engine idle normally (800+/-) rpms the AC cycled.
Does this sound to anyone like the AC Hi/Lo pressure switch is on the fritz? Maybe low on refridgerant?
I tried something else the other day.
When sitting at a stoplight I kept the engine revved to 20000-2500 rpms. AC stayed on with no issues.
When sitting at a stoplight and letting engine idle normally (800+/-) rpms the AC cycled.
Does this sound to anyone like the AC Hi/Lo pressure switch is on the fritz? Maybe low on refridgerant?
AudiWorld Senior Member
Joined: Aug 2002
Posts: 659
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From: Boise, Idaho
Fans are OK now? -->
I think that was the last thing to get fixed...
I can't remember if your vent air gets warm or not when the compressor cycles off. It's important to know.
When you high idle the engine the compressor will do a better job of compressing... duh!
This means the low side pressure is lower and the high side higher. Both of which will turn off the compressor. But your result is reverse, which would imply that you are over-charged.
For a cheap diagnostic, get an R-134a kit with the pressure gauge and attach it to the low side port. See what the pressure is when the compressor is on and off. You should see the pressure go low, the compressor cut out, then the pressure go back up and the compressor kick on. Report your result.
You could have cutoff switch issues on the high and/or low side, high or low refrigerant levels, clogged expansion valve, clogged lines, dirt, compressor failure, etc. Let's do some diagnostics before guessing.
I can't remember if your vent air gets warm or not when the compressor cycles off. It's important to know.
When you high idle the engine the compressor will do a better job of compressing... duh!
This means the low side pressure is lower and the high side higher. Both of which will turn off the compressor. But your result is reverse, which would imply that you are over-charged.
For a cheap diagnostic, get an R-134a kit with the pressure gauge and attach it to the low side port. See what the pressure is when the compressor is on and off. You should see the pressure go low, the compressor cut out, then the pressure go back up and the compressor kick on. Report your result.
You could have cutoff switch issues on the high and/or low side, high or low refrigerant levels, clogged expansion valve, clogged lines, dirt, compressor failure, etc. Let's do some diagnostics before guessing.
Thread Starter
AudiWorld Super User
Joined: Feb 2007
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Fans run great. Still haven't replaced the thermoswitch though..
When compressor cycles off it blows warm air, just like no ac.
I'll go out and get that kit tomorrow and do some testing after work and report back.
I'll go out and get that kit tomorrow and do some testing after work and report back.
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Joined: Jan 2005
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ive had A/C problems for the last 2 years on my vehicle
only to find out it was the actuating arm for the temperature regulator flap behind the HVAC unit that was broken.
anyways, after i fixed that, i was getting an intermittent fan control response. i checked the HVAC trouble code and 22.3/22.5 appeared, which told me that something was causing the pressure switch to cycle my compressor on and off. surely enough, my buddies and i hooked it up to an A/C pressure gauge and i had way too much pressure in there. we took some out and all is well now.
anyways, after i fixed that, i was getting an intermittent fan control response. i checked the HVAC trouble code and 22.3/22.5 appeared, which told me that something was causing the pressure switch to cycle my compressor on and off. surely enough, my buddies and i hooked it up to an A/C pressure gauge and i had way too much pressure in there. we took some out and all is well now.
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AudiWorld Senior Member
Joined: Aug 2002
Posts: 659
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From: Boise, Idaho
If you have thermoswitch already, replace that -->
You got Vag-Com (VCDS)? You can tell from measuring blocks why the compressor was turned off. Details in the Bentley... too involved to explain here.
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