W124 ignition power
 

I recently convinced my grandfather to buy a 124 300D to replace his stolen 123 280E telling him about the reliability etc. of the 124s. Having had the car for a month accessories no longer work from the ignition. I mean that with the ignition on you cannot open the windows or adjust the seat. However if you open the door you can so I know that the windows and electric driver's seat are fine. Are there any common culprits for such behaviour? Thanks