A/C guys, I need help!!!
Thread Starter
Racer
Joined: Dec 2000
Posts: 422
Likes: 0
From: Mesa AZ
A/C guys, I need help!!!
I just installed a new comp, condensor and receiver dryer, all went well till I tried to charge the system. I evacuated it for 3 hours, vacuum held perfectly all night. I went to charge the system but I can't get the compressor to start so I can't get the freon into the system, I'm showing about 110lbs press on the low side. Any help appreciated, I'm working on a 98 with climate control.
Last edited by chadman; Mar 25, 2009 at 12:05 PM.
Tech Contributor
Joined: Jan 2007
Posts: 19,453
Likes: 1,158
From: Dyer, IN
I just installed a new comp, condensor and receiver dryer, all went well till I tried to charge the system. I evacuated it for 3 hours, vacuum held perfectly all night. I went to charge the system but I can't get the compressor to start so I can't get the freon into the system, I'm showing about 90lbs press on the low side. Any help appreciated, I'm working on a 98 with climate control.
Pro
Joined: Jan 2006
Posts: 643
Likes: 2
From: Alexandria Northern Virginia
Should not have to jumper anything....cutoffs are there for a reason.
If you have your gauges hooked up, you need to open the blue valve so you can let pressure do its job. You fire up an empty compressor (no oil, gas, etc) thats hard on the parts and not necessary. You can do initial charge with the car off. Pop a can into your gauges and let it fill at least to even out the pressure between the can and the system....
You say it held vacuum so you know it will draw anything in as soon as its introduced. Remember, you charge through the blue valve
Cassidy
If you have your gauges hooked up, you need to open the blue valve so you can let pressure do its job. You fire up an empty compressor (no oil, gas, etc) thats hard on the parts and not necessary. You can do initial charge with the car off. Pop a can into your gauges and let it fill at least to even out the pressure between the can and the system....
You say it held vacuum so you know it will draw anything in as soon as its introduced. Remember, you charge through the blue valve
Cassidy
Drifting
Joined: Jan 2001
Posts: 1,347
Likes: 4
From: Slidell La
Should not have to jumper anything....cutoffs are there for a reason.
If you have your gauges hooked up, you need to open the blue valve so you can let pressure do its job. You fire up an empty compressor (no oil, gas, etc) thats hard on the parts and not necessary. You can do initial charge with the car off. Pop a can into your gauges and let it fill at least to even out the pressure between the can and the system....
You say it held vacuum so you know it will draw anything in as soon as its introduced. Remember, you charge through the blue valve
Cassidy
If you have your gauges hooked up, you need to open the blue valve so you can let pressure do its job. You fire up an empty compressor (no oil, gas, etc) thats hard on the parts and not necessary. You can do initial charge with the car off. Pop a can into your gauges and let it fill at least to even out the pressure between the can and the system....
You say it held vacuum so you know it will draw anything in as soon as its introduced. Remember, you charge through the blue valve
Cassidy
The ONLY time you can add liquid is ENGINE/COMPRESSOR OFF. If you do this engine running or start too soon you will blow the compressor from liquid ingestion.
Melting Slicks
Joined: Apr 2007
Posts: 3,290
Likes: 0
From: Willow Springs IL
You can SLOWLY add liquid into the suction side of the system with the car running. 134A should be charged as a liquid anyway because when charged as a gas the blend doesn't stay completely suspended. You should not have to jump out any low pressure switch or cutout to get the compressor to run.
Le Mans Master
Joined: Feb 2006
Posts: 5,267
Likes: 40
From: Phoenix AZ
When I charge a system from scratch, I always add the first can to both low and high sides at the same time in liquid (upside down) with the engine OFF. This way it will take the can much faster. Have a bucket of hot water to dunk the can in (it will get cold) and you will get more out without the car running. Close the high side and start car and AC. You should be able to charge from the low side now.
You might even have to clear a code or two first.
You might even have to clear a code or two first.
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Advanced
Joined: Feb 2005
Posts: 69
Likes: 0
From: lambertville mi
i would think if you have 110 on the low side the comp would cycle on and off using the low pressure switch built into the system. The comp should run until your low pressure switch opens, somewhere around 35 to 50 psi on your low pressure gauge (the blue one). good luck
Le Mans Master
Joined: Dec 2008
Posts: 5,414
Likes: 25
From: Texas
When I charge a system from scratch, I always add the first can to both low and high sides at the same time in liquid (upside down) with the engine OFF. This way it will take the can much faster. Have a bucket of hot water to dunk the can in (it will get cold) and you will get more out without the car running. Close the high side and start car and AC. You should be able to charge from the low side now.
You might even have to clear a code or two first.
You might even have to clear a code or two first.
