AC issues (1 Viewer)

[flintknapper]

In my case, the entire compressor was replaced. I'm honestly not sure if the issue was the compressor or the sensor withing the compressor, nor am I sure if the sensor can be replaced separate from the compressor. All that being said, I, obviously, don't have a part number for the sensor.

It is available separately Toyota Part No.: 88336-50040

But the cost to remove a compressor and install the part would approach or exceed the cost of a 'reman' or even a new compressor in some cases.

The sensor is a basically a Clutch Lock Out Mechanism. When there is a significant difference in speed between the engine and the compressor, the sensor assumes the compressor has (or is trying to) lock up. So in order to save the serpentine belt (which drives everything) it shuts off the electromagnetic clutch (coil) on the compressor. Of course this won't help you if the bearing in the clutch pulley has seized...but will save you if it's the compressor.

I don't know why any decent aftermarket compressor (with the same feature) wouldn't work BUT if the sensors they use are cheap and not synced with factory specs then it could well pose a problem.

 

[nissanh]

It is available separately Toyota Part No.: 88336-50040

But the cost to remove a compressor and install the part would approach or exceed the cost of a 'reman' or even a new compressor in some cases.

The sensor is a basically a Clutch Lock Out Mechanism. When there is a significant difference in speed between the engine and the compressor, the sensor assumes the compressor has (or is trying to) lock up. So in order to save the serpentine belt (which drives everything) it shuts off the electromagnetic clutch (coil) on the compressor. Of course this won't help you if the bearing in the clutch pulley has seized...but will save you if it's the compressor.

I don't know why any decent aftermarket compressor (with the same feature) wouldn't work BUT if the sensors they use are cheap and not synced with factory specs then it could well pose a problem.

Just curious of the location of this said sensor? Isn't there is a single wire to activate the clutch? What measures the RPM of the compressor?

My 92 corolla also has the clutch disengagement at below idle RPM (has its own drive belt). The idle-up VSV (vacuum switching valve) mounted on the firewall failed making the RPM to drop upon the AC turns on. Soon after that, I see the compressor clutch disengages! Just a rev makes the clutch to engage!! There is only 1 wire to magnetize the clutch, so I am confident the RPM signal is signaling the ECU to cut the power to AC compressor.

A compressor with low compression also shows the similar symptoms at idle no AC and higher RPM's blows cold. Most unbranded AC compressors show it soon after it is put into use.

Thanks!

 

[toyuda]

On a slightly related topic, does anyone know the location of the AC filter dryer on a 100 series and how simple it is to get at to replace?

 

[flintknapper]

Just curious of the location of this said sensor? Isn't there is a single wire to activate the clutch? What measures the RPM of the compressor?

The sensor (though replaceable) is integrated into the compressor (those with the feature) and it is located at the rear of the compressor.

The sensor reads the relative rpm of the compressor this is sent to the ECU which is monitoring the engine rpm. The two are compared.