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2006 E350
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Discussion Starter #1
I just replaced AC compressor because of bad bearing, however after purging system and putting vacuum on sysem the compressor won't turn on to take a charge of R134. Does the system need to be conected to a computer to activate compressor?
 

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E320/E250 Bluetec Ford F350 6.7l
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Can't tell you what engineers programmed into the newest computers with wheels, but on classic AC system you need at least 30 psi of refrigerant to activate the low pressure switch and start the compressor. The can of R134 gives about 100 psi or 60 psi on low level. Did you put some refrigerant before starting the engine?
 

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Discussion Starter #3
Can't tell you what engineers programmed into the newest computers with wheels, but on classic AC system you need at least 30 psi of refrigerant to activate the low pressure switch and start the compressor. The can of R134 gives about 100 psi or 60 psi on low level. Did you put some refrigerant before starting the engine?
I have 80 psi on can and hooked up to the low pressure side but the system would not take refrigerant?? I didn't know if the compressor needs to be hooked up to computer to tell it to turn on so it would take refrigerant.. I hope this helps
 

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Discussion Starter #5
If you can't put the pressure in, that means you have blocked connections.
You should vacuum the system before putting refrigerant BTW.

Yes I did vacuum system and it is in vacuum as we speak. I confirmed no blockage prior to connecting new compressor. I will check electrical connection at compressor maybe that isn't fully connected?? Any other suggestions??
Thanks
 

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Discussion Starter #7
So you have vacuum on one side of connection, 80 psi on other side and you still insist there is no blockage?

Negative, I evacuated system from low pressure side and system held vacuum then removed evacuation pump before trying to put refrigerant in. Are you telling me that I should put vacuum on high pressure side and pull refrigerant in from low pressure side without vehicle running?? Ive never done this before
 

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No. You vacuum the system, close the valve on the charging manifold, make sure the vacuum hold and than hook up the refrigerant tank and open the valve.
 

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Discussion Starter #9
No. You vacuum the system, close the valve on the charging manifold, make sure the vacuum hold and than hook up the refrigerant tank and open the valve.[

I did this it held vacuum, and when we went to add refrigerant it took about 1/4lb then stopped the pump never kicked in which makes me wonder if you need a computer to manipulate pump into turning on. My guess is when the system senses no refrigerent it shuts the pump down. We need to get the pump on for system to charge correct??
Please advise, -- I really appreciate your feedback and thanks for the help.

Steve
 

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Discussion Starter #12
AC problem fixed

1/4 of refrigerant should give you min 30 psi required for compressor start. What is the gauge showing now?

Sorry not home right now will reply later with feedback
FYI
The dealership connected their computer which bypasses low refrigerant pressure switch to activate compressor. If compressor doesn't turn on system will not take refrigerant. There was no blockage in system. Hope this helps others with similar problems of rechargeing ac system.
 
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