This is a hefty leak. Try using your blacklight at dusk or dawn, maybe even in the dark. It's surprising how much a well lit area "bleaches" out the reflective effect of the dye. Keep a strong flashlight handy to aim at any dye stains that you see, because you can see the dye in the black-lit area but it's too dark to see the parts with your eyes in the dark.
Ford trucks most common AC leak areas are hoses, connections, condenser and compressor, in no particular order.
Probably leaking in the evaperator. Its behind the dash board so you would be able to see the leak. May need to get an electronic leak tester and put it up in the vents to confirm.
When you check the pressure the following day, is it holding the charge? That is not clear from what you wrote. If it will take a charge then it is loosing R134A plain and simple. You just haven't found the leak. Have you checked the Schrader filler valve to see if it leaks? Could also be seals at or around the compressor, could be where the evaporator lines go into the condensor. Could be a pinhole leak in a line. If the refrigerant is getting out then there is a hole or bad seal or O ring. Are there bubbles in the glass? Also have you felt the line from the compressor to the evaporator to see if it is in fact cold but perhaps a diverter door isn't opening under your dash? Meaning a switch is bad or door is stuck or a vacuum line that operates the door is bad or something in the vacuum lines prevents the system from blowing cold into the cab meanwhile the compressor and cooling system is working?
Niggle the girgleton fertahsmin
2005 F150.
Charged it with 134a, pressures are good. Blows cold 40-50 degrees, but it never lasts longer than a day. Then blows 80-90 degree air. I've put dye into the system twice, got a black light and spent about 1.5 hrs looking for a leak. No leak. Compressor turns on and off and looks to be working normally. Anyone have any ideas what the problem is? Any ballpark of cost if I take to a mom and pop shop?
Thanks
