Hi. I'm new to the Forum and need some advice. I have a problem with my air conditioner cutting off at random. It could happen any time, no pattern. Sometimes at start up with a cold engine, the compressor won't come on and will come on after a few minutes of driving. At other times, it will be cooling well when driving and suddenly cut off and after a few minutes or half an hour it will cut in again. The compressor has been serviced and it's in good order. Fans are working. Gas is at the correct pressure. Dryer and pressure switch are new. Condenser is new but the problem still persists.
Looking forward to hearing from anyone with advice.
Regards ~ Denzil Sequeira

 

Bear in mind the refrigerant is added by weight, not volume. How was the refrigerant charge level determined?

Check the wiring loom and connections to the compressor for damage or poor connections.

This appears to be an issue with the transducer, or the connection to it on the high pressure line between the compressor and condenser.

 

Thanks for your quick response. I think the refrigerant was added by reading the pressure. However, if it was a refrigerant volume/weight issue, why should it be random cutting in and out without any pattern ?

Will check the wiring loom and electrical connections.

Thank you ~ Denzil

 

Sounds like the switch (just to the left and rear of the radiator) is bad: any green foam showing. Other choice, you may have overfilled the Freon (ain't legal to do in the US, but you can release some of the pressure: there is a YouTube).

Also, you can read the error codes for the AC unit: search for it.

 

Thank you for your message. Are you reffing to the pressure switch? If you are, that has been changed as well. Will look for codes on my scanner.

 

I have personally seen faulty transducers/pressure switches new out of the box.

The fact that your issue is intermittent indicates the transducer may be to blame.

 

Okay. Will check with a new switch. Thanks.

 

Open up the compressor clutch relay and check the contacts inside. It will likely be burned up from all the amperage that relay takes. You can either clean the contacts or just replace the relay with another one from the boot for a rear fog light relay instead. This isn’t guaranteed to fix your problem but it’s definitely worth doing before going any further even as a maintenance prevention.

Just unplug the pressure switch first and see if there’s any oil inside. If there is, then the switch must be replaced. If you do end up replacing the switch, I’m going to highly suggest evacuating the refrigerant out *before* replacing the switch. There’s a schrader valve underneath the switch that's *supposed* to hold the refrigerant in but, it’s likely that valve has been in the open (down) position for only 25 years so… it will likely continue to stay that way until it gets replaced along with the switch and o ring. What I’m saying is that the refrigerant will all release if you take the switch out before evacuating the system.

 

Did this problem begin before or after your compressor was serviced? I wonder if there is too much oil in the system. I don't know what I'm talking about when it comes to a/c, but I had an issue similar to this on a different vehicle years ago after having the system serviced. They ended up evacuating the system again and physically dumping out the oil from the compressor so they could measure how much was in there vs how much is recommended. It had too much oil in it, and whatever they did fixed it, but I don't remember the details. Just a thought. Definitely check the other suggestions first.

 

Hi all,

Thanks Than all your guidance and advice. It appears to be the pressure switch (when I tap it with a spanner, the compressor turns on).
I've ordered a new switch (which may take a few weeks to reach me in Goa). After changing the switch, I'll keep you all posted.
Thanks again ~ Denzil

 

Hi. Thank you all for your help. It was actually a loose connection in the pressure switch. It's now working perfectly. Thanks again ~ Denzil

 

We are noticing the increasing problems with electrical connections as
these cars age.