83 300sd new to me
 

i just got this car. previous owner said the windows sunroof and hvac fan all quit working from setting. i don't have a wiring diagram yet so can any one tell me where to start looking? is there a common area that could affect these circuits? everything else seems to work just fine

Also i am missing the drivers seat adjuster knobs that go on he door. Is there a source for these little knobs?