recent early morning problems starting sd 300. At ignition (which is slow after car sits idle) door locks rise and lock at least 2 times. After driving throughout the day all is well. But problems appear again next morning. Help? Problems began after compressor belt was replaced. Is there a vacuum line near there? Thanks

If it's an 81-85 300SD, my guess is that lock-unlock switching mechanism in the central locking pump is starting to go. The central locking system in a W126 is independent of the vacuum systems run by the engine driven vacuum pump.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD