A/c Problem?
sport01
07-03-2007, 01:45 PM
I have a 2000 blazer and the a/c works great for the first 5 to 15 minutes or so. Then it just stops blowing cold air. It still will blow air but it's not cold. After you turn it off and it sits for a long time it will work again for a few minutes. Any ideas? THANKS.
MT-2500
07-03-2007, 01:53 PM
Give us your pressure readings low and high side at idle and at 2K RPM with compressor running.
You will need something like one of these.
http://www.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Code=RefrigerantGaugeSets
You will need something like one of these.
http://www.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Code=RefrigerantGaugeSets
sport01
07-03-2007, 03:00 PM
I don't have a gauge.
MT-2500
07-03-2007, 04:40 PM
Got any good buddies with one?
You might check your AZ or local parts place.
But do not let them sell you a one hose one can one gauge death kit.
Some have a rent/loan deal on tools.
A gauge set is the only proper way you can check or test a AC system.
Good luck
You might check your AZ or local parts place.
But do not let them sell you a one hose one can one gauge death kit.
Some have a rent/loan deal on tools.
A gauge set is the only proper way you can check or test a AC system.
Good luck
ericn1300
07-04-2007, 12:03 AM
MT is correct, you need a high side and low side reading. The refill kits only give you the high side.
Also if you've refilled the freon more than once you have to realize that the same leak the lets out the freon lets air in when the pressure gets low enough. Air does not compress like freon (if it did we all be saving a lot of money). The compressed freon actual becomes a liquid that can be blocked by the specific gravity of air trapped in the uper part of the system, which cooling down might correct as the freon becomes gaseous agian, not unlike a vapor lock in a fuel system. Any system that has lost enough pressure to equalize with the atmosphere should be repaired, vacumm evacuated and recharged by weight.
Also if you've refilled the freon more than once you have to realize that the same leak the lets out the freon lets air in when the pressure gets low enough. Air does not compress like freon (if it did we all be saving a lot of money). The compressed freon actual becomes a liquid that can be blocked by the specific gravity of air trapped in the uper part of the system, which cooling down might correct as the freon becomes gaseous agian, not unlike a vapor lock in a fuel system. Any system that has lost enough pressure to equalize with the atmosphere should be repaired, vacumm evacuated and recharged by weight.
blazee
07-04-2007, 05:44 AM
MT is correct, you need a high side and low side reading. The refill kits only give you the high side.
Also if you've refilled the freon more than once you have to realize that the same leak the lets out the freon lets air in when the pressure gets low enough. Air does not compress like freon (if it did we all be saving a lot of money). The compressed freon actual becomes a liquid that can be blocked by the specific gravity of air trapped in the uper part of the system, which cooling down might correct as the freon becomes gaseous agian, not unlike a vapor lock in a fuel system. Any system that has lost enough pressure to equalize with the atmosphere should be repaired, vacumm evacuated and recharged by weight.
All the refill kits I have seen only give you the low side pressure readings.
Also, anytime that the system has equalized, or the system has been opened, I strongly suggest replacing the accumulator.
Also if you've refilled the freon more than once you have to realize that the same leak the lets out the freon lets air in when the pressure gets low enough. Air does not compress like freon (if it did we all be saving a lot of money). The compressed freon actual becomes a liquid that can be blocked by the specific gravity of air trapped in the uper part of the system, which cooling down might correct as the freon becomes gaseous agian, not unlike a vapor lock in a fuel system. Any system that has lost enough pressure to equalize with the atmosphere should be repaired, vacumm evacuated and recharged by weight.
All the refill kits I have seen only give you the low side pressure readings.
Also, anytime that the system has equalized, or the system has been opened, I strongly suggest replacing the accumulator.
Sparky1349
07-04-2007, 02:27 PM
Hey Sport01,
It is possible that your system is freezing up, although 15 minutes sound a little quick for that, it kind of depends on if you live somewhere where it is real humid. If you have a thermometer turn the system on high and close all of the vents except the the one on the passenger's side. If the temperature is close to freezing like 33-35 degrees then freezing is a possibility, also check and see if the drain is dripping water, if the evaporator is getting to cold then it won't drip any 'cuz it's all freezing on the evap.
If you want to properly diagnose this you have to get a set of gauges. Harbor Freight has a cheap set (www.harborfreight.com (http://www.harborfreight.com)) for less than $40 incl. shipping.
Good Luck,
Sparky
It is possible that your system is freezing up, although 15 minutes sound a little quick for that, it kind of depends on if you live somewhere where it is real humid. If you have a thermometer turn the system on high and close all of the vents except the the one on the passenger's side. If the temperature is close to freezing like 33-35 degrees then freezing is a possibility, also check and see if the drain is dripping water, if the evaporator is getting to cold then it won't drip any 'cuz it's all freezing on the evap.
If you want to properly diagnose this you have to get a set of gauges. Harbor Freight has a cheap set (www.harborfreight.com (http://www.harborfreight.com)) for less than $40 incl. shipping.
Good Luck,
Sparky
Automotive Network, Inc., Copyright ©2024