Electrical issue-windows and sunroof
 

I have a 1991 300E 4 matic with 225,000 miles. Recently when I turn off the ignition switch-the radio stays on-just mentioning this in case it is connected to the problem i need fixed-NONE of the windows open-and the sunroof doesn't work-I checked the fuses-no such luck they are good-My boyfriend seems to think there is a circuit breaker of some sort involved-but he is a Jaguar nut-so is somewhat at a loss when it comes to a Mercedes...Any ideas? There is no clicking or humming or ANY sound when you try to open the windows-sunroof-they just don't work....(outside temperture is NOT a factor-it has been 50 degrees out here recently...)
Thanks:

Hi Boneea , double check the fuses or just replace them , the windows should be on 2 fuses (one frt window ,one rear window , on opposite sides per fuse ). They can look OK but aren't . After that you will have to start tracing the circuits to determine the cause , though it's unusual for all windows to go out . Did you just buy the car like this or is this a spontaneous failure . Good luck .

Your car has a "comfort" computer that operates the windows & sunroof. If this computer fails then all functions will stop.
There are 4 fuses involved in supplying power to this computer & ALSO a relay(clear) that powers the computer up.
Fuses 9, 2, G, & H.