[Rawknees'Turbo]

hcoles, those head units have three temperature sensors - one on the evaporator's in pipe, one on out pipe, and a room sensor that is beneath the cover, to the side of the LED display/sensor for remote control (there are a couple of small slits on the side of the cover and the room sensor is there - it basically looks like a short, thin black wire . . . can't see it without removing the cover/case however). I know this because I had to make mods to those when installing my aftermarket controller.

With my fan speed on the second from highest setting (not the "powerful" setting), and the remote control temp set at 61 (my aftermarket controller not operating at the time), the air exiting the evaporator is consistently in the 45-48 degree range (with aftermarket controller running the exit air temp gets much lower).

My model is GL24 (a/c version only - no heat pump function).

Based on what you've described above, it sure seems like there has been an error made in the amount of refrigerant added. Unfortunately, your best option at this point is probably going to be getting someone else to look at/test the system, as long as you can find a tech that you are confident he/she knows what they are doing (based on your remark about installer business going quiet).