1998 C230 Air Conditioning help needed
 

I have a 1998 C230.

My problem occurred a week ago when we were on the highway.
My air conditioning stopped cooling. I set the unit a few degrees lower
and increased the fan speed. This did not help.
I decided to head back home.

After I existed the freeway, about 2 miles on surface streets, it began working again, very well.
I have used the car twice since then. It seemed a little slow to initially cool, but is working fine.
I have not had it back on the highway yet.

Any suggestions would be appreciated.

P.S.
What is a good manual for A/C repair on this car?
I bought the Chilton's version, and it very lacking.

Mine did something similar to that yersterday. I had left the setting on 74 from the previous day when I had the AC on (keeps it from getting too cold). The car had been parked in the shade and so was pretty cool inside. I pull out into the sun and the heat goes on!!. So I am driving in the hot sun with the heat on. So I pushed the temp down to 64 but this had no immediate effect, heat still on. So I pushed it down to 55, still heat coming out. Finally I went all the way to LO or whatever it says and it finally started blasting out cold air. My conclusion was that there is a delay in the feedback loop for the temp control. Sounds sort of like what you are describing.

Mike

The heater valve (mono) is the most likely problem.