S250 ac repair help

[Rotaxxx]

We'll finally it's warming up here and tried the ac in my newly acquired s250 and it don't work! First of all when you hit the switch for ac the light doesn't come on, also when you crank the temp to cold it blows pretty warm air. As if it's hot, and not outside temp air. Also ac compressor does not engage. Not sure we're to start on this, any help would be great! Thanks all.

 

[farmshop]

I would check for refrigerant in the system. You could check fuses. I would guess it is low or empty of freon.

 

[Bobcatdan]

I would check for refrigerant in the system. You could check fuses. I would guess it is low or empty of freon.

Outside of checking fuses and relays, have a shop the works on equipment AC look at. Leaks can be very hard to find and may take several tricks to find. Dye often doesn't work because the pin hole leaks are so small. I had the best luck evacing the system, fill with nitrogen then spraying everything with a special soap. Do it yourself AC kits first came legal here in Wisconsin a year or so ago so I have never played with them. With my general AC knowledge, I can't see how those work well at all.

 

[Tazza]

Outside of checking fuses and relays, have a shop the works on equipment AC look at. Leaks can be very hard to find and may take several tricks to find. Dye often doesn't work because the pin hole leaks are so small. I had the best luck evacing the system, fill with nitrogen then spraying everything with a special soap. Do it yourself AC kits first came legal here in Wisconsin a year or so ago so I have never played with them. With my general AC knowledge, I can't see how those work well at all.

I had a bad relay on mine.
It could be a few things, open low pressure switch (low refrigerant), bad fuse, bad relay.
I checked mine by powering the clutch to see if there was any refrigerant in the system.

 

[Rotaxxx]

I had a bad relay on mine.
It could be a few things, open low pressure switch (low refrigerant), bad fuse, bad relay.
I checked mine by powering the clutch to see if there was any refrigerant in the system.

Thanks for the help so far guys, I will dig into it in the next few days. On a side note, the DIY kits you can buy I heard once you put them in the system you can't use regular r-134a in it again. Any truth to that?

 

[farmshop]

Thanks for the help so far guys, I will dig into it in the next few days. On a side note, the DIY kits you can buy I heard once you put them in the system you can't use regular r-134a in it again. Any truth to that?

they make r 134 kits that are just refrigerant with a connector. It is easy to overfill a system. Anyone can buy r 134 and guage kits. 100 or so dollars can buy guages.

 

[Tazza]

they make r 134 kits that are just refrigerant with a connector. It is easy to overfill a system. Anyone can buy r 134 and guage kits. 100 or so dollars can buy guages.

I can't see why you can't use R134a either. Not sure how you are meant to get the correct charge in them though, at least with cars, the weight is on a sticker.
I'm not sure if you can work on sub cooling and/or super heat to work out the correct charge in an automotive AC system like you do on AC systems in houses.
Over here in Australia, we can't buy refrigerant over the counter, you need a license. I can understand that for ozone eating ones, but ones that don't damage the ozone layer like R410a we can't touch either.

 

[farmshop]

I can't see why you can't use R134a either. Not sure how you are meant to get the correct charge in them though, at least with cars, the weight is on a sticker.
I'm not sure if you can work on sub cooling and/or super heat to work out the correct charge in an automotive AC system like you do on AC systems in houses.
Over here in Australia, we can't buy refrigerant over the counter, you need a license. I can understand that for ozone eating ones, but ones that don't damage the ozone layer like R410a we can't touch either.

best way to tell the charge is with guages. You watch low and high side pressures till they are at spec most systems you try to stay below 250 psi on high side

 

[Tazza]

best way to tell the charge is with guages. You watch low and high side pressures till they are at spec most systems you try to stay below 250 psi on high side

Just how well does that work? as the gas has different boiling points at different temperatures. If you work on a temperature/pressure chart i can see you getting it pretty close though.
If the receiver drier has a sight glass, this could make it easier as you charge till there are no bubbles in the sight glass.

 

[farmshop]

Just how well does that work? as the gas has different boiling points at different temperatures. If you work on a temperature/pressure chart i can see you getting it pretty close though.
If the receiver drier has a sight glass, this could make it easier as you charge till there are no bubbles in the sight glass.

It will get you close especially if you can do the service at your ambiant operating temps. Ideally you would vac it down check for leaks by seeing how it holds vac and then weigh in the correct amount of refrigerant. I know john deere doesn't have sight glasses in many of there dryers anymore for some dumb reason

 

[Tazza]

It will get you close especially if you can do the service at your ambiant operating temps. Ideally you would vac it down check for leaks by seeing how it holds vac and then weigh in the correct amount of refrigerant. I know john deere doesn't have sight glasses in many of there dryers anymore for some dumb reason

Airconditioning has interested me for a while, i always thought if you wanted colder, add more gas, but that is not the case. The youtube videos i have watched on the net have really been great explaining all the things you do to get the correct charge, and to not over charge or you risk pump damage.
It's just a shame in .au we don't have easy access to refrigerant, it's all licensed, even for non ozone eating ones.
I actually had a unit at home that didn't cool since i bought the place, i evacuated it and recovered the refrigerant, it had half the charge it should have. I weighed back in the correct amount from other recovered units with R22, now it works like it should. Sadly i haven't tried to find the leak with soap bubbles, i just tightened the connections.