t800 only blows hot air

Coolant flow control valve on passenger side lower firewall.

 

no 134a in it

 

Technically, the compressor won't kick on if there's not enough freon in the system. Unless it's my truck where the low pressure switch seems to be messed up.

But yeah. If it's low. There won't be any cold air. Put ac gauges on the system and see what the EQUALIZED PRESSURE reads without compressor running.

 

Have you confirmed actuator is working? May have lost its power or ground. If ac is working properly then only other option is to shut off the valve that controls coolant flow to heater core. Think someone mentioned that already. I had an older truck that didn't have a actuator. It had a valve that worked on a cable from the dash, to control temp in the cab. It would only shut off mayby 90% of hot coolant flow. So my ac didn't get quite cold enough on really hot days. So shutting off the flow completely with the under the hood valve did the job.