I have a 94 Toyota PU with a 22RE engine. Is it true that the air conditioner compressor is supposed to automatically disconnect when the engine is under a heavy load? I haven't noticed it in my truck.
Phil
- posted
20 years ago
a/c compressor disconnect under load
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- posted
20 years ago
I don't think so. The only disconnect is when the A/C loads the idling engine up enough to drop the speed below the A/C amplifier's low-RPM cutoff.
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- posted
20 years ago
My understanding is that the VSV (Vacuum Switching Valve) handle heavy acceleration cut off of compressor. Ever see old cars of the 40's with vacuum windshield wipers where the faster you accelerated the slower the wipers went? A vacuum completes the circuit and compressor engages and low vacuum (heavy acceleration) opens it disengaging the compressor.
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- posted
20 years ago
The VSV that is connected with the A/C system is to boost the idle speed via the idle-up valve. It works in conjunction with the A/C amplifier to keep the engine from idling at too low a speed and thereby turning the compressor at too low a speed to work properly. Since my A/C compressor is disconnected right now, I was able to utilize the A/C idle-up VSV to effect a push button fast idle setup. With the A/C clutch disconnected and a jumper in the low pressure switch, hitting the A/C button will cause the VSV to open and let vacuum flow to the idle-up valve and the idle rises as dictated by the setting of the whte knob atop the idle-up valve.