I have a mystery ac freon leak on 2000 Chrysler T&C.

Take it to an A/C specialist, if it leaks out in 1 day it will be very easy to spot the leak.

dye is the older bright, bright red visual to naked eye. I have 50 years experience in aurto repair including AC repair. telling me to "take it to a specialist " isn't answering the question. sorry!

The red dye came in the 134A can.

I REALLY, really do know what I'm doing guys.

You’re an old hand, you already know the answer, you just don’t like it very much. For the rest of the world... If it leaked out and it didn’t leak out where you looked, then it leaked out where you didn’t look. In this case, it’s the “I checked that” items you’ve fudged. We both know that there isn’t a chance in the world that you spent 8 hours disassembling the dashboard to put your eyes on that front evaporator, or 3 to stare at the rear. If you’re a clever old hand, you did look at the drip tube that exits from the evaporator condensate drain instead and check for red dye on the ground. You did say “previously” so if that was last year and there isn’t any red dye left that would explain it, but if it’s losing the charge in a day, either you are not making enough condensate to carry enough dye to where you can see it, or it’s dripping on the road or in parking lots where the driver doesn’t check for dye on the ground and it’s not making condensate when it gets back home. You can try using a swab, even a little paper towel rubber banded on a screwdriver, to see if there’s any dye residue inside the drain tubes. There can also be no dye drip if a plugged front drain line caused the corrosion in the first place, it can hold a lot before it soaks the carpets. You can get a faster read on the evaporator leaks with an electronic halogen leak detector at the drain tube exit. It’s heavier than air, you won’t get as good a reading from the ducts. The electronic detectors are at good prices online at places like Amazon, brick and mortar prices tend to be high, I don’t know if chain stores loan or rent them. Again, if the drain is really well plugged it won’t come out there, but a large leak as described will fill the duct and spill out the vents, but iirc it closes the duct flaps when it’s off, which would make the gravity exit for a heavy gas going back out the fresh air intake be the wiper box drip drain tubes left and right. If you were going to invest the time to get in there you would have bought all the replaceable parts in advance and after 4 hours taking the dashboard apart and just one look at the dirt plugged, corroded evaporator you would have immediately changed the heater core, the evaporator and the expansion valve. Likewise the same rear parts. And at least one of them would have been covered in red dye. As a last, you need to do more about the system oil level than just add the chart volume for the parts you replace. if it’s blown the charge out a few times, the compressor oil level is unknown, but unlikely to be anything other than almost empty. There’s no way to check the oil level. You have to remove the compressor, tip it over, and pour the oil in it out, then add the full compresssor oil volume to it (and the volume for any other parts.) if there is *any* grey or brown in the oil that you dump out, the compressor has to be swapped, it’s been grinding itself up, and you have to flush the metal particles from the lines and the condensers etc. if you see black, it’s probably from the inside of a hose. You still have to flush everything. When you’ve flushed you score those parts as containing no oil as if you had changed the part for a new one and add oil to make up for what will be clinging to the inside.