Help with Volvo VNL780 A/C

The pressure switch you can run a jumper wire across to see if the compressor engages. But it should build enough pressure with one full can to where that step is not necessary.
You can hold the can about 3 o'clock and shake it vigorously and it will all go in there.
Your high and low side should be different size connections so it's hard to mess up. The majority of leaks are at a hose gasket o-ring or the shrader valve on one of the ports. Many times the leak is very small and a home mechanic can tackle it with R134a with stop leak. It might fix it or it might slow it down at least for the summer you'll have AC. If it doesn't then I would get it professionally serviced to locate the leak. There is no sense tackling a leak if you don't have a vacuum pump. Advance will loan you a vacuum pump with a deposit or CC#.
Walmart sells a decent refill kit for the home mechanic. It has a blue top with a gauge. You read the gauge with the handle out and don't let it exceed the blue shaded area on the gauge. It should take 1-2 cans. Follow the instructions on the can. But that is only good for adding a can or two and not replenishing after a repair. After a repair the system has be flushed and a vacuum pulled.

 

Hey i have the same problem, the AC button lights up, but compressor doesnt work, it turned on once, and worked for a few hours, than stopped working again. I had freon refilled and there is no leaks, I have no clue what else it could be.

 

Hello. I'm also having an issue with my AC. When I turned my AC on, no air is coming out of the vents. (Air was coming out in the morning). Can someone tell me where the pressure switch is at so I can run a jumper wire and see if it engages. If it's from low free-on will it also not blow air if I turned the heater on? I turn the dial to hot and still no air came out.

It's a 2008 780 with D13. Thank you in advance.

 

i drove an 04 volvo (cdl training), and has bad a/c. The mechanics recently replaced the a/c compressor and it got worser.

 

I have a 2006 , 780 with D12 on it. My problem is, when I turn the AC on. Air comes out from the vents, but after a while stop blowing. I've replaced the AC blower and the blower regulator, but still the same. But it only happens on the cab, the sleeper unit works fine, all the time. Please I need help

 

Turn the fan off and then on. See what happens

 

if you don't have any codes it sounds like your ac controls are bad..

 

Hi guys. I own Volvo 780 07'. Lately I been in hot Arizona and my AC worked without a problem day and night. But yesterday all of sudden I got message on my dash computer saying I have to check climate system on next stop. One minute later the message disappear and AC start working correctly. I kept idling another few hours and noticed that compressor clutch was all the time engaged. No kick off... A few hours later I started the truck and when I got on the freeway same message start showing up and disappearing up to the moment I constantly stayed on. I went to the shop and after a few tests they decided I have leak on one of the sleeper lines. To fix it they recommended replacing parts of the lines (apparently disconnecting would be dengerous because the line can get broken) and sleeper condenser. But they needed a few hours to do so. I couldn't wait until next day so I took the risk and asked for recharging the system and try to survive hot night and next day. So far after 7 hours system works great and blows really cold air. But the compressors clutch is still engaged. So what it means? Is compressor broken? Or do I need to replace high low pressure sensors? Or should I follow what they say and spend a lot of $ to replace all the parts they recommending?
Please advise.

 

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