lyttek
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- Jan 13, 2009
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Trying to figure this one out...
At static, engine off, both high and low sides of the A/C read about 90 psi.
Start the engine, kick the A/C to max, and pressures are 30 psi on low and 120-125 psi on high at idle. Running the RPM up a little does little to nothing on high side, low will drop to 25psi at which point the compressor kicks off. Once the low side comes up a bit, then it cycles on/off as normal. I've added a little freon to keep from cycling quite as much, pressures don't change, just reduced the cycling a little.
Now, after about 10 minutes of this, the compressor kicks off and stays off... and both low and high sides are static at 80psi.
How is that possible??? Static pressure lower on both sides compared to when first starting the tests?? I wasn't watching when the high side dropped, so no idea yet exactly what happens. If I turn the A/C off for a bit, the pressures stay the same, but the compressor will start again. This cycle repeats... cooling stops, turn the a/c off a few mins, then it will cool again.
It's decently cold when it's working... I don't have a thermometer yet to check the air temp.
Other than the low and high side pressure switches, what else would control the a/c clutch?
When the first 'shut off' cycle appeared, I shorted the low-side pressure switch and the compressor did *not* kick on... can high-side switch be tested the same, or ??
At static, engine off, both high and low sides of the A/C read about 90 psi.
Start the engine, kick the A/C to max, and pressures are 30 psi on low and 120-125 psi on high at idle. Running the RPM up a little does little to nothing on high side, low will drop to 25psi at which point the compressor kicks off. Once the low side comes up a bit, then it cycles on/off as normal. I've added a little freon to keep from cycling quite as much, pressures don't change, just reduced the cycling a little.
Now, after about 10 minutes of this, the compressor kicks off and stays off... and both low and high sides are static at 80psi.
How is that possible??? Static pressure lower on both sides compared to when first starting the tests?? I wasn't watching when the high side dropped, so no idea yet exactly what happens. If I turn the A/C off for a bit, the pressures stay the same, but the compressor will start again. This cycle repeats... cooling stops, turn the a/c off a few mins, then it will cool again.
It's decently cold when it's working... I don't have a thermometer yet to check the air temp.
Other than the low and high side pressure switches, what else would control the a/c clutch?
When the first 'shut off' cycle appeared, I shorted the low-side pressure switch and the compressor did *not* kick on... can high-side switch be tested the same, or ??