Hello, good folks,
Have no power going to AC compressor.
Checked compressor clutch - turns freely (when off).
Check resistance on compressor connectors - has resistance.
Clutch was not engaging with AC on and off whatsoever.
Check low/high pressure - stable at ambient temperature (the correlated low pressure tube psi and ambient temperature). Checks out.
I don’t think I have any leaks.
Power to clutch has no voltage whatsoever. Tried with ignition on, engine on, ac off / ac on. Can’t freaking find a fuse or relay to that power. Why am I not getting power to ac compressor/clutch.
I don’t know what else to look for. Anyone has any advice? Thank You
2016 Cascadia DD13. No power to Air Compressor.
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I had one in recently that was not getting power to the clutch and it was the TRANSDUCER switch on the a/c line near the dryer. I could move it around and it would run. I just installed a new transducer and harness end and that took care of it.
Might be a bad pressure switch. Probably located on the dryer. Can be changed without losing any refrigerant. It’s a common thing. I’d change it, and if that’s not the problem, leave it, keep the old one for future quick diagnosis. You can try unplugging it, and jumping the plug with a paper clip. Might work. Sometimes the plug itself goes bad. I just had to replace mine. Next on the list of suspects is the temp sensor probe. Located inside the cab. Small sensor with a wire probe going into the a/c evaporator. Those two things control power to compressor. Your Truck may be different than mine. Fuses etc. Mine also has a constant power supply wire running to it that comes from the starter. The plugs themselves at compressor seem to go bad, from heat and excessive movement from the fan engaging.Forever237 Thanks this.
What does stable at ambient temperature mean?
That don't tell the people anything
And that's not how it works
If you got less then 50. The low pressure won't kick on. If you got too much. The high pressure won't kick on.
There is certain correlation between outside (ambient) temperature and pressure at this ports (I don’t know but guessing freon expands faster than air). Attached photo. So if the correlation is off, you either have low/high amount of freon.
That’s what I understood yesterday, scrolling through internet. Correct me if I’m wrong
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Pressure stabilizes when it's off. YES.
But takes awhile these days.
Correlation with ambient Temps. YES. It expands and contracts with temperature. My car reads 120psi equalized in july. 5psi in January.
So cars don't run the compressor with defroster in the winter. Not enough pressure.
That's why it's always best to leave ac alone till it gets warm. More accurate pressures in the heat. I donate my freon to people needing top offs. I buy the 30 pound containers. But wait till it's at least 80*
Putting all that aside. You're asking for help. And saying it's copesthetic with ambient Temps tells the people NOTHING. It still boils down to 2 posts mentioning numbers.
What's your EQUALIZED pressure. And posting that number.
If you don't have enough. It won't work.
If you have too much. It won't work.
There's a minimum and maximum and neither side cares about ambient Temps.
I can't say for sure as I live in dry air. But humidity might play a part also.
On that note. Start with posting equalized pressure. And the forum can go from there.
In the motorcycle forum..they have good compression. Good compression. WTF does that even mean? How do you know you have good compression when you don't even know what it should have.
Anything short of factory spec is not good compression. 100 out of 170 is definitely not good compression. That cylinder is almost dead.Last edited: Jun 3, 2023
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