White 2-105 AC charge

I need a little help. I bought a 2-105 this winter and I have
tried to add Freon because my ac is not blowing cold air.
Warning light is on the control panel.
I have hooked up my charging kit to the only port on the
compressor that it fits. My gauge maxes out right away and it
will not take any Freon. I am using 134 which the previous
owners said he was using. The compressor clutch does not
kick in.
Can anyone send me directions/video service manual info?

There is nothing I n my owners manual or service manual.

Thanks

There's a little silver tin cap that you have to take off on that fill valve. There's a square headed stud under it. You have to turn that to open that valve up before it'll take the Freon.

You have to get the compressor running first.

Look for any pressure switches that may be unpluged, bad switch, fuse, whatever could stop the compressor from coming on.

Once you get it running, check for cold before adding charge. The 134 is very sensitive to over charging. It needs to be charged by weight, or high/low/temperature chart. Guessing will generally get it over charged.

You need to call a local AC mobile service guy and have him come out and find the leak, or get some of the dyed refrigerant and find it yourdelf. No use throwing away money on 134a that isn't going to stay in the system.

The experts say that you need to pull a vacuum on it before trying to add refrigerant in order to get a meaningful charge.

Thanks for all of your input. The opening of the valve from rrlund is my missing link.
I agree with finding the leak but on a tractor that is almost 40 years old, it could be a money pit. If I can get by with a couple cans of R-134 a year, I would be good with that.
Thanks Again!!

There could be many reasons for the A/C not to work. Lack of refrigerant is only one of them. Among them are the low pressure switch, the high pressure switch, fuse for the compressor, or a bad clutch.
Add to that, air in the system, too much or too little oil in the system, bad compressor, plugged receiver/dryer, just to name a few more.
Adding refrigerant before diagnosis is just asking for failure. The only way to properly diagnose the state of charge is with a set of gauges and a charging chart.
First step is to determine if there is enough refrigerant in the system to activate the low pressure switch. This switch shuts off the compressor when the charge is low. Usually cuts off around 25psig. Activates at 45psig.
Once you have determined tat there is enough refrigerant to operate the system, check for power at the low pressure switch. If there is power there, you can momentarily jumper it to see if it turns on the compressor.
At this point, the high pressure switch should be on unless it has failed. Also note that systems that were originally R-12 did not use a high pressure switch in most cases.
Next, check for power at the compressor connector. If you have power there, and the clutch still does not engage, then the clutch is bad.

As you can see, there is more to an air conditioning system that just putting in more refrigerant. In my opinion, those charging kits should be banned. The general public is simply not qualified to service refrigeration systems.