hi guys i was wondering how a the control unit on a car recognizes that the window is fully up? do they use a current sensing circuit or something?

 

Current sensing is usual.

 

would this circuit work?

http://www.romanblack.com/current.htm

 

It will sense current above a threshold level, but alone can't distinguish between a normal motor start-up current surge and a stalled motor situation. It does not switch the motor off.
Be aware that vehicle mods are contrary to the Terms of Service of this site.

 

thanks i am aware that vehicle mods are prohibited this will not be a mod but a replacement of a current faulty system

 

GM call them Electronic circuit breakers.
Max.

 

is there enough room to put in a limit switch? might be simpler, open the circuit when the window is full up. another switch to open he open circuit when full down.

 

Simply using a limit switch is not safe. Think trapped fingers etc.

 

Does anyone read the TOS?

http://www.allaboutcircuits.com/l_tos.html

 

thanks i am aware that vehicle mods are prohibited this will not be a mod but a replacement of a current faulty system

It doesn't matter. Mods, repairs, replacements, etc are all prohibited. And by the way, this does classify as a modification.

I expect this thread will be closed very soon.

 

Ok. Time to enforce the rules. No discussion on mods, repairs, replacements etc of automotive electrical system allowed on AAC.

 

Actually, automotive repairs are allowed for, contrary to modifications. However, we don't allow for patch-up jobs or go-arounds. You have to ask for instructions on how to bring your vehicle back to its original state, for the thread to have a chance of staying open.
Component identification and sourcing, this kind of thing.

Clearly, this particular thread doesn't belong to this category and will stay closed.