Steve,

I've been repairing European cars for over 20 years and I can assure you without any doubt that it does indeed happen in cars. It doesn't matter where the pressure drop comes from, if the low side of an R-12 system falls below 30.1 psi and the compressor is not disengaged the evaporator WILL freeze up, assuming there is sufficient refrigerant to absorb the heat in the evaporator.

A quick search of the bulletin board at www.aircondition.com reveals 4 pages of posts/replies regarding "evaporator freezing". Several replies mention low refrigerant charge as the likely cause. I'm sure I could find more specific references in the tech manuals at the shop.

It's no skin off my nose if you don't believe me but this is a well documented phenomenon. I've personally witnessed it many times in my own cars as well as customers' cars.

Regards,

///MikeR
'93 190E 2.6 Sportline