I tried to add new refrigerant last year with no luck. I had added dye and leak sealer the last time a couple 3 or 4 years prior but it was pushing hot air again. Anyway I'm not a quitter so I tried again this year to add refrigerant. For reasons I do not recall I squeezed the fitting and the pipe it was connected to together and the refrigerant started going in! So apparently the connector wasn't pushing the Shrader valve in. If I let go it stopped so I just help it till the can was empty. Could be the connector which worked fine the previous time. Or it could be the leak sealer in the stuff I had put in the year before made the Shrader valve stick. I couldn't see any leaks with the yellow glasses and light.

 

What kind of refrigerant did you use? And was it ever converted?

 

R134a- This is the OE system in 94, California truck.

 

Don’t really need to convert the system outside of buying adapter fittings. You can just add r-134. Yeah not recommended but if not leaking it works. My system is ice cold this way. Anyhow, this is a difficult one to diagnose based off of what you say.
if the system is charged and it’s hot out and checking the system, with the doors open and on full blast, the compressor should be fully engaged and not short cycling.
I bought gauges and vacuum of Amazon for under 150. Best way to go about his is to first check pressures on high side and low side and report back. Check with a/c running and the let us know the ambient temp. Once we have this info, gonna tell you to pull a negative vacuum and the. Check gauges after an hour or so to verify there is still vacuum and no leaks.

the big question here is “ is the compressor on the motor engaged, front housing spinning”?

 

Thanks for the offer of help FatMike I wouldn't even know how to begin to connect to a charged system. If I was gonna pay a guy to empty it properly I'd probably just have him test it. I was just posting an update of sorts since I complained last year to let people know that squeezing the connection together indicated to me the Shrader valve was not being pushed in by the connector that came with a large can of R134a from AZ.