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klutchdust's avatar
klutchdust
Explorer II
Jul 26, 2013

Will a compressor run without freon?

Neighbors 2004 Forest River TT air conditioner is not cooling. Fan, blower runs fine, compressor also as it is hot to the touch. My experience has been if there is no freon the compressor will not run because of low pressure cut out switches. Do these roof mounts have them? I looked for a model or brand name but nothing there. My original thought was the start capacitor could be bad but the compressor runs. This trailer is used mainly in the desert and has received zero maintenance. Unit has R-22
Any advice appreciated.
  • Now the question of repairability comes into play. Once the leak is found and repaired the chances of damage to the compressor by running it without freon is of concern. For me , I would replace it , the owner? We shall see.
    Appreciate the feedback. Happy motoring.......
  • Auto compressors will run w/o Freon,....the real old ones anyway, but all the later models ('90+) have the LP switch inline, so they won't.

    Dint know about Roof Air till now.
  • Ranger Smith wrote:
    2edgesword wrote:
    A compressor will run without freon but won't cool.


    Compressor will not run without freon. The low pressure switch shuts it off.


    The OP is talking about Roof Top AC units, NOT Auto Dash Air units. There is NO switch or system on RV Roof top units that prevents the Compressor from running when their is NO Freon. Depending on the type leak (Large or small) the other problem on Roof Top AC units is HOW MUCH oil leaked out when it lost its charge. If the oil loss is significant (you will see the oil in the pan), then it is not a good idea to fix the leak and recharge. Better to replace the roof top unit. If the compressor is HOT to the touch then the Freon is gone. Replace the roof top upper unit. Doug
  • Ranger Smith wrote:
    2edgesword wrote:
    A compressor will run without freon but won't cool.


    Compressor will not run without freon. The low pressure switch shuts it off.


    RV A/C units do not have low pressure switches they will run without gas until they lock up or the internal thermal opens up, and yes it will damage the compressor running without gas. They get hot because there is not cooling from the cool vapor coming back form the evaporator (suction line)they lock up because the oil will go out into the system and not circulate back to the compressor with out gas in the system.

    Denny
  • 2edgesword wrote:
    A compressor will run without freon but won't cool.


    Compressor will not run without freon. The low pressure switch shuts it off.
  • Most and I believe all freon compressors depend on the freon to cool the compressor as it runs. Damage can occur if you run very low or completely out of freon.

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