I have been having an issue with the sunroof either not always closing or won't unlock (1987 944). I followed Clark's Garage test procedures, limit switch 1 is fine, console switch is fine, output voltage on main sunroof relay. I pulled the relay and tested input voltage. Got 12V on R with ignition in position 1, when I turned to position 2, got 12V at R, but only 4.7V at A. This would seem to indicate a ground issue. The question is which ground point is most likely to need to be cleaned to get 12v at A?