A/C problem has me stumped...
A/C problem has me stumped... I have already searched through this forum and haven't found anything quite like what I'm seeing.
A/C compressor clicks on (as far as I know clutch is engaging) does not cycle at all but no cold air at all from the vents. All the HVAC controls seem to function fine, but just to be sure I ensured that the T by the ECU/PCM and the vacuum line by the map were fine (didn't find anything obvious anyway).
I have one of those bottle kits with a gauge on it for the low psi side, when the compressor clicks on it pulls down from about 45 psi to 35 psi right in the middle of the green but none of the lines seem to draw condensation or feel cool to the touch. A/C worked perfect before, but the car sits a lot in my garage so it's been a while since I turned it on, I normally try and run it even in the winter to keep everything lubed in the system. Car only has 33.8k miles and A/C never made any weird noises and it still sounds like it did before, just no cool air.
Thanks for your help in advance!
Brad
A/C compressor clicks on (as far as I know clutch is engaging) does not cycle at all but no cold air at all from the vents. All the HVAC controls seem to function fine, but just to be sure I ensured that the T by the ECU/PCM and the vacuum line by the map were fine (didn't find anything obvious anyway).
I have one of those bottle kits with a gauge on it for the low psi side, when the compressor clicks on it pulls down from about 45 psi to 35 psi right in the middle of the green but none of the lines seem to draw condensation or feel cool to the touch. A/C worked perfect before, but the car sits a lot in my garage so it's been a while since I turned it on, I normally try and run it even in the winter to keep everything lubed in the system. Car only has 33.8k miles and A/C never made any weird noises and it still sounds like it did before, just no cool air.
Thanks for your help in advance!
Brad
Hmm, I've never heard of an A/C system having vapor lock before. Not sure how that much moistore can get into a factory A/C system that has never been serviced before. Have you seen something like that happen before?
Have you checked the heater control valve? Its what allows coolant to flow through the heater coils which is usually located directly behind your evaporator coils. If it is faulty when you have the ac on it will blow warm air., even though you have a good charge. 2cents.
There's also a vacuum line going from the rear of the intake (near the MAP sensor) that controls the baffles. It's a small hard plastic line that can get brittle and break. I've heard of guys doing !AIR and blocking this line off.
Although, i'd think your lines should still get cold.
Although, i'd think your lines should still get cold.
Have you checked the heater control valve? Its what allows coolant to flow through the heater coils which is usually located directly behind your evaporator coils. If it is faulty when you have the ac on it will blow warm air., even though you have a good charge. 2cents.
There's also a vacuum line going from the rear of the intake (near the MAP sensor) that controls the baffles. It's a small hard plastic line that can get brittle and break. I've heard of guys doing !AIR and blocking this line off.
Although, i'd think your lines should still get cold.
Although, i'd think your lines should still get cold.
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my car sat most of the winter here in al and a few days ago i went to tun on the ac and it was not to cold so i hooked up my gauge and it was also in the green(blue the next color on the gauge being the right amount) so i gave it a little more and it started blowing perfect ice cold.
try puting a little more in.
try puting a little more in.
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Verdad Gallardo my car sat most of the winter here in al and a few days ago i went to tun on the ac and it was not to cold so i hooked up my gauge and it was also in the green(blue the next color on the gauge being the right amount) so i gave it a little more and it started blowing perfect ice cold.
try puting a little more in.
try puting a little more in.
TECH Enthusiast
Joined: Feb 2008
Posts: 503
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From: Ventura, Ca
There is a pressure switch that keeps the A/C from coming on and burning up the compressor if the R134 is too low. Sounds like you need a charge and that't all. That is also why they recommend turning on the A/C every week or so to keep the seals oiled and working.
Ok, last night I started the car and turned on the A/C and it would not click on at all. I hooked up the gauge to the low pressure side and it showd about 40 psi static. After reading the information I found at this sight: http://www.aircondition.com/tech/questions/82/
that means that the system is really low on freon. Sunday when I got the system to click on (it read a slightly higher static pressure due to higher ambient temps, which is why I think it clicked on) it only pulled the dynamic pressure down 10 psi which according to the above sight it should be pulling it down from about 80 psi to 30ish psi. This sounds like low sunction from the compressor indicating a bad compressor and low freon. Since the compressor doesn't create enough suction it never pulled the pressure down far enough to cycle itself on and off which is the normal indicator of low psi in the system. Does that logic make since?
that means that the system is really low on freon. Sunday when I got the system to click on (it read a slightly higher static pressure due to higher ambient temps, which is why I think it clicked on) it only pulled the dynamic pressure down 10 psi which according to the above sight it should be pulling it down from about 80 psi to 30ish psi. This sounds like low sunction from the compressor indicating a bad compressor and low freon. Since the compressor doesn't create enough suction it never pulled the pressure down far enough to cycle itself on and off which is the normal indicator of low psi in the system. Does that logic make since?
The most likely problem is low charge due to a leak. Have the system evacuated 
and recharged with the proper weight and recheck. If it is low, inspect for a leak with a cheap ultraviolet light and protective eyewear from a parts store.
and recharged with the proper weight and recheck. If it is low, inspect for a leak with a cheap ultraviolet light and protective eyewear from a parts store. If it were low, then wouldn't the compresor have cycled when it came on? If the compresor hadn't just came on and stayed on then i would agree with that logic.
If your low oil light came on, would you spend 2 hours reading internet articles and then diagnose the level sensor? Or would you check the basics first like the oil level?
Marc 85Z28,
I do have access to a low pressure gauge (I have a set of R12 gauges but haven't gotten the conversion kit for the lines yet). You are right that that article is generic, and I don't know much about this new variable diplacement unit on this car (didn't even know thats what it was). But your the first person to even say anything about the compressor. I guess all I'm saying is please explain how you have come to the conclusion that it's just low on freon?
And if that were the case then why didn't it click on when I attached the can of freon and opened up the valve (gauge read 40 psi before opening valve to can and then 80ish psi after opening)? If the system hasn't fully evacuated itself (no pressure in the system at all) then why would I need to empty the system and then pull a vacuum on it to refill it? Shouldn't just topping it off again allow the system to work nominally again (except for the leak)?
Thanks for you help!
Brad
I do have access to a low pressure gauge (I have a set of R12 gauges but haven't gotten the conversion kit for the lines yet). You are right that that article is generic, and I don't know much about this new variable diplacement unit on this car (didn't even know thats what it was). But your the first person to even say anything about the compressor. I guess all I'm saying is please explain how you have come to the conclusion that it's just low on freon?
And if that were the case then why didn't it click on when I attached the can of freon and opened up the valve (gauge read 40 psi before opening valve to can and then 80ish psi after opening)? If the system hasn't fully evacuated itself (no pressure in the system at all) then why would I need to empty the system and then pull a vacuum on it to refill it? Shouldn't just topping it off again allow the system to work nominally again (except for the leak)?
Thanks for you help!
Brad
Marc 85Z28,
I do have access to a low pressure gauge (I have a set of R12 gauges but haven't gotten the conversion kit for the lines yet). You are right that that article is generic, and I don't know much about this new variable diplacement unit on this car (didn't even know thats what it was). But your the first person to even say anything about the compressor. I guess all I'm saying is please explain how you have come to the conclusion that it's just low on freon?
And if that were the case then why didn't it click on when I attached the can of freon and opened up the valve (gauge read 40 psi before opening valve to can and then 80ish psi after opening)? If the system hasn't fully evacuated itself (no pressure in the system at all) then why would I need to empty the system and then pull a vacuum on it to refill it? Shouldn't just topping it off again allow the system to work nominally again (except for the leak)?
Thanks for you help!
Brad
I do have access to a low pressure gauge (I have a set of R12 gauges but haven't gotten the conversion kit for the lines yet). You are right that that article is generic, and I don't know much about this new variable diplacement unit on this car (didn't even know thats what it was). But your the first person to even say anything about the compressor. I guess all I'm saying is please explain how you have come to the conclusion that it's just low on freon?
And if that were the case then why didn't it click on when I attached the can of freon and opened up the valve (gauge read 40 psi before opening valve to can and then 80ish psi after opening)? If the system hasn't fully evacuated itself (no pressure in the system at all) then why would I need to empty the system and then pull a vacuum on it to refill it? Shouldn't just topping it off again allow the system to work nominally again (except for the leak)?
Thanks for you help!
Brad
Just a low side gauge is not enough. And the 80psi you're reading with the can attached? That's actually reading the can pressure. You really need a set of gauges. You can have good low side pressure, while having no compressor operation due to low system charge. Just because the low side reads 40 or so does NOT mean the system is fully charged.
If I were in your situation, I would evacuate
the system, recharge, and then continue diagnosis if necessary. Marc,
Thanks for the info, and I absolutely agree on covering the basics first!
Since the system will no longer switch on (assuming this is because the system is low) can I force the compressor on like you can with the old on/off compressors by shorting the pressure switch circuit? I thought that having the freon can hooked up to the circuit might help but it didn't' have an effect. The pressure switch for these cars is on the line not the accumulator close to the upper shock mount plate correct?
Thanks for the info, and I absolutely agree on covering the basics first!
Since the system will no longer switch on (assuming this is because the system is low) can I force the compressor on like you can with the old on/off compressors by shorting the pressure switch circuit? I thought that having the freon can hooked up to the circuit might help but it didn't' have an effect. The pressure switch for these cars is on the line not the accumulator close to the upper shock mount plate correct?
