Air conditioning system questions not answered elsewhere

[FireFox31]

Thanks for your input. I will keep revising the top post as I gather more information.

[Ozark Lee]

Hi,

Lets assume low pressure switch is bad and jumpered. Can i use A/C?
If i can't, what if i connect a switch to pins and manually on and off can i use A/C?
Is there a temporary solution for using A/C with bad low pressure switch?

Thanks,

It is very rare for the low pressure switch to go bad. 99.9% of the time the reason the switch is open is because the pressure is too low.

Running the compressor on a low refrigerant charge will ultimately destroy the compressor and contaminate the rest of the system with the shards of metal that come from the compressor when it grenades. The price of repairing the system goes up by a factor of about 10 when the compressor lets go so it is highly risky.

...Lee

[noev70t5]

I was planning on a seperate post but saw no reason if this one's already here.

Q: My 1998 v70 t5 's AC compressor and my motor fan stay on (they dont cycle) when I turn on my AC. Is this ok?

Is there something my AC is telling me when it doesnt cycle the 'normal' 30 seconds to a minute like its done since ive owned it?

Freezing air comes out, and if I leave the car/AC on for a while it seems like it holds up.

Dont fix it if it aint broke?

Always appreciate the help!!

-Noe

[mwlaser]

2000 volvo s70 GLT ha s a high pitch whistle around the low pressure port when I turn the car off and it last 30 sec and not your normal freon sound as it can be heard by people standing around the car. The unit was just tested and charged but never got below 50 degrees F . Also the air does work but not well at higher outside temps. It appears the clutch does not cycle and stays engaged. Freon is in the green zone and goes red when I pull the electrical connector on the freon line by the fire wall.
I did add 12 oz of freon after the experts tested it and recharged it.Most likley the evaporator is leaking but what is this whistle noise

[101]

Bumping this because I have the same issue on the 98 V70 that noev70T5 has. The compressor runs continuously.

The refrigerant charge is good and the electronic climate control does what it needs to to maintain the cabin temperature. I'm convinced I can make ice in the cabin.

Probably related - on super hot and humid days after a extended period of time the evaporator will freeze up. Airflow gets very limited. A few minutes of disengaging the compressor and letting the evaporator melt and all is well again.