Hello, My cars A/C has recently decided to become possessed. The lights on the A/C controller randomly come on and off. The blower comes on but is not controllable. The compressor works, but is also randomly working. I keep getting a consistent code of EO 13 for the rear A/C controller. The problem is this is a coupe and does not have one installed.
I completely disassembled the A/C controller and verified the resistance checks on all the control wheels potentiometers. I have all of the buttons now working. I recently replaced the blower motor due to a failed bearing. I had a spare controller suspecting an issue with the harness, but that made no difference.
I do not want to purchase another ACC controller and just have the same issue. Any ideas on this one? Any ideas would be appreciated.

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1989 560SL
1986 300SDL
1983 300D (Burning Jet-A)
1982 240D
1995 S600