While I do turn mine on for a few minutes once a week or so in the winter, I have never just left it on. The additional wear and tear on the compressor for no good reason is mostly why, and I can feel the power drain on the engine from the AC and look forward to winter when I can turn it off. I have never had my AC refuse to work at the beginning of AC season. But, to each his own.

Regarding the pressure switches, on the 124 there are two. The one for the compressor is the one where the wires plug directly onto the switch. The switch with pigtails is the one for the AUX fans. Perhaps the 210 is the same.

The pods should be no factor. Jumper the pressure switch and see if the compressor engages.

Also, you heard a squeal. Be sure your serpentine belt is tight. If it is loose and lets the compressor slip, the AC system will shut down.

__________________
2012 E350
2006 Callaway SC560