Before I Search through the gazillions of threads on the ACC, I'm looking for some input first.

Every so often I will start the car ('87 300SDL) and although the A/C is selected and the temperature turned low enough, I get no cooling. The Fan just goes to Max. and blows in ambient air. Turning the ACC to 0 and then back to Normal (with A/C) makes no difference. Nor does changing the temperature or changing from Economy back to A/C.
Without changing anything on the ACC, if I stop the engine and then re-start it the ACC starts operating normally with A/C on and cooling nicely

This happens 2 or 3 times a week out of 20 - 30 starts/stops.

Is this the onset of flakey ACC operation possibly due to bad solder joints or should I be looking somewhere else?

__________________
1991 M-B 560SEL Arctic White/Grey 99,000 Miles
1987 M-B 300SDL Ivory/Palomino 229,000 Miles (sold but never forgotten)
2006 Volvo XC70 Blue/Beige
1999 Porsche Boxster Arena Red/Savanna Beige
1986 Porsche 928S Goldweiss/Brown

could be a marginal low pressure cutout, due to switch or low refrigerant. Could be worn relays, I think your vehicle may also have a comp. speed sensor of some sort. Could be heat valve check sticking up so sometimes it mixes heated air with cool. Just a start.

__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

I'm fairly sure the Compressor is not coming on when this happens, although I haven't peeked under the hood to check. I will next time it happens.
The Refridgerant was replaced last year and no sign of leaks. When working properly there is plenty of cooling.
Can I dis-assemble the relays to check for dirty contacts? Are these in the fuse box with the others?
I think there is a Speed Sensor on the Compressor. How do I check if it is working OK?