I recently replaced the temp sensor switch on my 1989 300 SEL due to the a/c cutting off. Stupid me I lost all the refrigerant, at any rate I thought for a while the problem was fixed but yet again the a/c cut off while driving. Outside air seems to always be 89 plus when this occurs. Also, if I stop the car and restart, 9 times out of 10 the a/c will resume blowing cold air. Any suggestions and should I not have converted to 134r ?

For a few years now I've been using Enviro-Safe in my cars,(http://www.es-refrigerants.com/), in place of R134a. Costs less, cools better, takes less refrigerant and is easier on the environment.

Anyway, I recently bought a 1983 380 sel that had the same cut-off problem you do. The problem disappeared after I converted it to Enviro-Safe.

that is a 103 engine car with a speed sensor on the compressor and a o/heat sensor on the engine.either one can cause the shut off and come back on with restart.check your serpentine belt and see if it's loose[this can make the speed sensor kill the a/c relay] one easy way is to find a/c relay and jump pins 15&87 and go drive the car and make sure that the refrigeration system is good.then you will know what you are dealing with.

__________________
David S Poole
European Performance
Dallas, TX
4696880422

"Fortune favors the prepared mind"
1987 Mercedes Benz 420SEL
1988 Mercedes Benz 300TE (With new evaporator)
2000 Mercedes Benz C280
http://www.w108.org/gallery/albums/A...1159.thumb.jpg

David , thanks for the reply. I know where the relay is and I've read other threads regarding jumping the pins, but exactly what are we talking about ? are you saying to temporarily wire the sockets (pins) with the relay switch pulled?
jc

Also do you know where the o/heat sensor is on this engine. Thanks jc