Check AC pressure and it goes up and down?
- Thread starter wixman
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Low on freon
We need more info.
What are the high side pressures?
What are the low side pressures?
What is the outside temperature?
Is the fan on high and all doors open?
Is the suction line cold all the way back to the compressor?
PS: Those cans with a low side guage are useless. You need 2 guages to properly charge an AC system.
What are the high side pressures?
What are the low side pressures?
What is the outside temperature?
Is the fan on high and all doors open?
Is the suction line cold all the way back to the compressor?
PS: Those cans with a low side guage are useless. You need 2 guages to properly charge an AC system.
Originally Posted By: Chris142
We need more info.
What are the high side pressures?
What are the low side pressures?
What is the outside temperature?
Is the fan on high and all doors open?
Is the suction line cold all the way back to the compressor?
PS: Those cans with a low side guage are useless. You need 2 guages to properly charge an AC system.
Good info: An old timer in the AC business gave me this info, and I tend to agree.
Cold weather is not the time to evaluate AC systems operation properly. The compressor will kick on and off, it needs hot weather to operate properly. That's not to say there is nothing wrong with it, but I'd wait till the weather gets into the 70's before I messed with it.
We need more info.
What are the high side pressures?
What are the low side pressures?
What is the outside temperature?
Is the fan on high and all doors open?
Is the suction line cold all the way back to the compressor?
PS: Those cans with a low side guage are useless. You need 2 guages to properly charge an AC system.
Good info: An old timer in the AC business gave me this info, and I tend to agree.
Cold weather is not the time to evaluate AC systems operation properly. The compressor will kick on and off, it needs hot weather to operate properly. That's not to say there is nothing wrong with it, but I'd wait till the weather gets into the 70's before I messed with it.
40 is too cold to try to get a proper charge unless your starting with a empty and vacummed system and are using a scale.
Originally Posted By: mechanicx
I think this is normal for just about every A/C system. Most use a cycling clutch. Unless it is a variable displacement GM it is normal, especially in cooler weather. What vehicle is it?
The hard part though is determining how quickly it should cycle. To just say it should cycle is a little misleading.
I think this is normal for just about every A/C system. Most use a cycling clutch. Unless it is a variable displacement GM it is normal, especially in cooler weather. What vehicle is it?
The hard part though is determining how quickly it should cycle. To just say it should cycle is a little misleading.
40F is the upper end of the cycling pressure. It's going to cycle non stop at that temperature.
wait until it is warmer.
Most modern compressors cycle.
Too rapid or never cycling shows a problem - wrong refrigerant amount or a bad switch, maybe even a a puked compressor.
When you check the low side pressure, do it only when the compressor clutch is engaged, not in the rest cycle. The rest cycle reads much higher pressure, and you won't really be filled enough.
Too rapid or never cycling shows a problem - wrong refrigerant amount or a bad switch, maybe even a a puked compressor.
When you check the low side pressure, do it only when the compressor clutch is engaged, not in the rest cycle. The rest cycle reads much higher pressure, and you won't really be filled enough.
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