New thing with windows

[Honolulu]

Recently I've been driving another German uber-coupe: MB 500 SEC. It's not mine, and sometime I'll have to give it back, but for now I'm "putting on some miles to see how well it runs" for the owner who has five other Benzes. Anyway...

The windows on the 500 work when the key is out of the ignition and driver's door is open. I see the door jamb has two contact switches, and I guess there's a relay connected to one of those, which powers the windows.

Now, right off, I'm lazy. So has anyone made this happen in their coupe, and can you detail how it was made to work? I once heard a rumor that late model coupes had this feature, but again, being lazy, I've not looked into the electrical diagram.

If no one pipes up, I'll have to go into the diagram and see what needs to be made to happen. But again, being lazy, it may be a looooong time before that goes off, so I'm open to comment, suggestion, etc.

TIA !

 

[Malc]

THe older R107 model mercs have the same feature, the 280,350,450,500SL and SLC models from about 1971 on, nicknamed the Panzerwagon for the build of the things.
Anyway the interior light switch in the door jam (Drivers side only) activates a relay in the window circuit allowing the windows to to operate. It's a pretty simple circuit.

My now gone Audi Quattro estate had the same feature, but it worked off the central door locking system. If the car was not locked you could work the windows, if it was locked then you couldn't. However if the car was locked but the keys were in the ignition switch, even in the off position they would work. I do have the circuit diagrams for the Audi somewhere and could trace it and find the components required.

Some cars use other methods such as time delay circuits, seat pressure switches or combinations of all the above.
Malc
Edit: I'll draw a sketch of how to do it and post later....

 

[Arde]

My 77 E24 had that also. You could also easily make the windows
work at all times regrdless of ignition. I don't see a problem with that.
A manual window can be rolled up and down even when the ignition is off.

 

[AndyM]

My '75 CSi does that, too. Never really looked into the wiring on it though -- that's one of the only things that I haven't touched at this point.

 

[tochi]

Safety

"Arde" said: "My 77 E24 had that also. I don't see a problem with that.
A manual window can be rolled up and down even when the ignition is off."

I would guess it lessens the chance of unintentional injuries to children, dogs and maybe even inebriated passengers.