Thank you for the suggestions regarding the air conditioning compressor cutting out on my w124.
I have disconnected the auxilliary water pump connector under the windshield reservoir. It was so corroded that I could barely get it apart. I used my A/C for at least 30 miles today and it cooled great, and the climate control held the temperature quite nicely.
Whether it works this well going to San Jose next Sunday, and through SJ to Oakland the following week, remains a mystery. Since it worked great in cooler weather but seemed to cut out in warmer weather, this makes me suspicious that something like coolant temperature, coolant volume, or something else was triggering the A/C compressor to cut out. I am a little suspicious about the aux coolant pump.
Nevertheless, I plan to bring another 12 pack of Coca Cola--JUST IN CASE
Thank you for the helpful suggestions. If the coolant pump disconnection fails to rectify the problem, I will investigate the Klima relay. I'm a little weary of bypassing it, as I do not want to lose power steering or something else if my compressor locks up.
I will keep you posted.