Date registered: Nov 2007
Vehicle: W140 Mercedes 500 SE, 1992, European, 410.000 km
Location: Slovenia (Europe)
Mentioned: 0 Post(s)
Quoted: 272 Post(s)
regulators from ebay fo 20 eur are known to cause similar problems. they usually work form several hours to several weeks. Mine started both leds in the dashboard at center vents like you described. so there is a big chance that this is a case if you have put in an aftermarket regulator.
If not, then check wires and connections which you moved.
the next idea is to remove minus terminal on a battery and wait some time. maybe AC control module needs some rest and all will be fine with new regulator if the current one is not that one for 200 - 400 eur (i do not know the exact price but they are expensive).
All I wish for Christmas is a smooth idle.