My 2002 F250 Truck (with V10 and 4 wheel drive) has a leak dripping onto the hot exhaust pipe at the Y (in front of the passanger seating area). I think this only happens when running the AC.
QUESTION: Is there (or should there be) a drain pipe / tube that drains the condensed water ?
There should be a rubber tube coming through the firewall into the engine compartment on the passenger side. It may have fallen off, and the condensate would then run down the firewall an drip wherever the lowest point is.
An A/C system is supposed to drip. Your system is doing what it is supposed to do. Whether the drips end up in the intended location is another matter; for now, it is harmless.
My 1999 Ford product has no drain tube and it is not supposed to have one. I suspect that drain tubes have been dropped because they tend to clog up. There is an opening in the bottom of the HVAC plenum that drains the condensate. The opening is placed so that it does not drip on the firewall.