ac pressure switch replacement

[jose4autos]

I have a 1996 honda civic, A/C not working (compressor not engaging-just random on-off). I had been suggested to check the cycle switch by shorting the 2-prong connector, "if it does not engage the compressor, then it's bad". with this information I assume it's bad. My question is I can see the cycle switch on top of the accumulator, but not sure if I should remove it with a wrench. Wouldn't the coolant leak out if I take it out? any idea how I should go about it?.. thanks..

[RonJ]

So when you jumped the switch connector, did the compressor clutch engage without switching on and off? Have you measured the refrigerant pressures on the high and low sides?

[jose4autos]

No I have not checked pressure on both Low and High. I did check the Low when I added refrigerant. funny thing, yesterday it the compressor was engaging fine and worked fine, but I think it was because it was 85degrees. It has been 94degrees the last couple of weeks here. I'm still not sure about the pressure switch (cycle switch), is it true that if you jump the two prongs together the compressor should engage? (when I tried it it did not engage).

[mk378]

Since it did [i]not[i] engage when you jumped the switch, something else is wrong.

Plug everything back in as stock and note what happens when you press the button. Does the condenser fan run? Does the idle speed increase? Is power applied to the compressor wire? Usually when the system works intermittently it is because the compressor clutch gap is too wide.

By the way, unlike most American cars, the system does not "cycle" on pressure. The switch it is there to shut down the compressor in case of abnormally high or low pressure. Under all normal operating conditions, the switch stays closed. The refrigerant must be removed before unscrewing the switch in the unlikely event that replacement is necessary. While still installed, test the switch with an ohmmeter it should be a closed circuit.