A/C problem

[Harry in Ky]

I couldn't agree more. 45 PSI is too high for a system operating normally (if that's accurate), but without two gauges, one is really flying blind. I find that a properly charged system, or at least close to that, will usually show a static pressure of around 70 PSI or so. That may vary a bit with ambient temps, but not that much. When the clutch engages and compressor is running the low side starts dropping and the high side starts rising. Where each finally settles down determines what (if anything) needs attention. I make that determination at high engine RPM, not at idle or slightly above.

 

[Mildthunder]

July 10, 2018 - YouTube

Took a video this morning. Was running fine yesterday

 

[Tx Jim]

Like stated before, we need to know the high side pressure also. Until we know that we are pissing into the wind.

If you'll read my 1st reply which is #6 you'll determine that I 100% agree with you to diagnose AC problems one needs to utilize both low & high pressure gauges

 

[Mildthunder]

Ok, you guys got me thinking about the 45psi on the low side, being kinda high. I let out a bit of charge, and now the compressor is staying running. Which makes sense, because when its 75 degrees out, it worked like a champ. As soon as it got hot out, the compressor started acting up. High psi cutoff prob was kicking in.

Tomorrow im gonna bring my high and low gauges and get some more readings. But i think im good now

Engine fan is working well, condensor, radiator, etc all been cleaned and spotless.

 

[Harry in Ky]

It's about time. That's what you should have done to begin with rather than asking questions no one can answer.

 

[Mildthunder]

It's about time. That's what you should have done to begin with rather than asking questions no one can answer.

Wow. I been a member of at least a dozen forums , from cars, to offshore powerboats, and everything in between. Gotta say, this forum isnt very welcoming.

I only asked this question because its well known that certain machines/vehicles are known to have common issues, and maybe this could have been something like "hey, check the high psi switch located in the roof , they are known to be faulty" or something along those lines.

If I was a master journeyman john deere a/c specialist , I wouldnt be here asking questions. I apologize that this tractor I run is 1 hour drive from the shop , and was trying to diagnose a problem in the field. It has 200 hours on it and has never been touched. Apparently it was overfilled from the factory.

In my automotive experience, 45psi for low side pressure on a 85* day, isnt all that out of line depending on the vehicle. Apparently it is on a john deere 5085E.

Anyhow, thanks for the chastising . Appreciate it

 

[Mildthunder]

For those who offered some insight, its appreciated. Thank you!

 

[DuckSlayer1017]

I agree with the pressure rising, but not spiking. When the compressor kicks out, the low side will rise but not spike.

I'm not going to give this much effort without knowing the low and high side pressure. Could be a switch, expansion valve, charge, lack of air flow on condesor/evaporator. I'd also like to know the resistance of the clutch coil. Is the clutch diode good? I've have many diodes fail under amperage load. The doide is on the power side(B+) of the clutch circuit to help with voltage spikes when it disengages

If it is a Denso compressor the clutch resistance is probably between 4 and 7 Ohms. If the diode is blown the clutch usually won’t engage.

Edit: Just saw the video, clutch resistance for that model is what I stated but probably closer to 5.2 Ohms. I can’t remember the spec off the top of my head but I’m a mfg engineer for the plant that makes those compressors.

 

[MilersoPisa]

I've had problems with the A/C recently. I guess it's the most common problem of vehicle owners. However, now I always check the aircon and change filters in time

 

[ann_ferg]

My Kubota is quite new, so I didn't have any problems with the A/C. But I actually had a situation when my home air conditioner broke down. It all started when the aircon started to make weird noises. At first, we didn't really pay attention to it. But every time we turned on the aircon the sound was getting more noticeable. So we called a technician from https://www.airconservicing.org/why-choose-us/. It turned out that the fancoil was simply worn out. The man told us that if we wouldn't call him the aircon could actually explode. We were terrified. Happily, now it works well. I also clean the a/c from time to time...