If you have dye in the system, operate the car for a good while with the a/c on. When you stop, have a container ready to catch the water draining from the evaporator. Pour it into a clear glass container so that it's easier to see.

If there's no dye in the glass, your evaporator is not the problem. There are all sorts of place where the system can leak, making it hard to see without special lighting equipment.

My 2 cents.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"