Ok, so my car was serviced for the ac and found the first time no leaks and good pressure, but needed further investigation on what the problem was, then further detection found to be low pressure switch failure, I called my Dad who has the same make and model as i do which is 94 850, and he said they had the same problem and the mechanic said to just bypass it by placing an insolated wire and bypass it. So i did, and works after 5 secs of turning the ac on, is this safe? Can this be a long term operation? the mechanic did say that if the ac does stop working by doing this, just turn it off for 15 minutes and then it should be good again.


Is this safe to do?

Not recommended. The pressure switch is intended to protect the compressor by preventing it from operating in a low pressure (low oil) environment. As long as there is sufficient pressure to move the oil around you are fine. If you lose pressure due to a leak, you risk the compressor.

If you are sure the switch is bad, change it sometime soon. You can check it for continuity with a multimeter.

Good luck!

Bypassing a low pressure sensor is a perfectly good method to troubleshoot the system, and if bypassing the switch allows the compressor to kick in, you're in good shape (sort of). The low pressure sensor is there to prevent the compressor from running if the pressure level is below the sensor set point. This is to protect the compressor. You should check the operating pressure in the system to determine if the problem is a faulty sensor, or if indeed it's doing its job. If it's just the sensor, replace it.... don't leave the bypass in place. The sensor is an on/off switch, which is normally closed.... a simple check for continuity (zero resistance) with a multimeter or test light, will tell you if the sensor is good or not. Don't run the system unless you're very certain that the refrigerant charge level is correct. The oil that lubricates the compressor will be lost if the refrigerant charge has leaked out, and running the compressor for any length of time without proper lubrication will allow you to ruin the compressor, thus testing the smooth operation of your bank account. Good luck

Marty

'96 855T

The refridgerant has been replaced first this year, and the other stuff has been in there for 4 years that I know of before! So the gy checked and there was no leak, anyone know where I can gte a low pressure for a decent price?