This has me baffeled.

The Texas heat is coming.
-No A/C [blower but no compressor].
-Aux fan under grill won't turn even when powered directley [via Bentley test].
-No sunroof.

Possible causes:
-Negative battery terminal disconnected while working then reconnected. In the past this disconnection has rendered the sunroof useless for a few days - as if the car needs a few days to relearn to open the sunroof.

-Operator error. Stupid me Connected a hi impeadance DMM across Hot and Gnd to check for power at the AUX fan relay. And there was an arc as I touched black to ground. But it should not be an issue b/c I was measuing V and doing it with a hi Z DMM. ???

But wait there's more:
-All fuses OK
-AND, ... drum roll please ... , removed the Neg terminal and then the DME for grins then reinstalled both. And of course the A/C compressor fired right up the first time I cranked the car.
-But then and only then - A/C hasn't worked since that one fluke. Can't reproduce it [haven't removed the DME a 2nd time but still...].

Im at a Loss:
-Power resistor on AUX fan could be out but why would that prevent the compressor from working?
-If it is out why did it decide to work after unhooking the DME?


???,
Ab