Power Window Winders

[Black1990jeep]

On my 1990 XJ 4 door I have power windows. want to be able to operate the windows without having to turn on the ignition. I sleep in the XJ and want to be able to adjust the window opening at night without having to turn the ignition key.
I figure the factory likely made the power windows only operate with ignition key on as a theft deterrent, so a thief can't open the window by using a coat hanger wire shoved in the window gap to operate the window switches.

So I want to have a dash mount toogle switch that will be able to energize the power window system, without energizing the ignition system. I can then open the new switch for when I park and want security, and close the new switch all night long for my night time needs of adjusting the windows.

Where in the circuit is a good place to add such a switch to bypass the ignition and energize only the power window circuit?

I assume someone has done this before, how did you do it?

 

[TRCM]

How's this ????



Sorry, couldn't resist......

 

[Black1990jeep]

Well that drill is a tool, and I am never adverse to another tool. might come in handy for other things.

Some research in the repair manual yields....

The windows get power from a violet wire coming out of a breaker at the fuse panel. Breaker is power by a bus bar or wire that also powers ABS motor, ABS computer, dashboard clock, and emissions counter. These are all powered on one pole on the key switch.

Since some of these draw power continuously, I will need to isolate the window circuit breaker input with a double throw relay. I dont want to drain my battery if I leave my new window bypass switch on while parked. The power windows should not consume any power at all when energized unless operated.

I will dig into this some more, let you know.

 

[Greenspan]

You could use a diode to isolate the power windows and prevent power from flowing back into the rest of the system.

Another approach may be to wire a second switch to the motors themselves. The motors should be isolated themselves by the normal switch.

Just spitballing here

 

[Black1990jeep]

Would not a diode give a drop across it when it is conducting?

 

[lazyxj]

The voltage drop across a diode is minimal, around .1-.2 volt, it's more important to have a diode rated higher than the expected load.
My 2001 XJ's power window circuit uses a 25-amp fuse, I would want a diode rated at least at this big or, preferably, higher, to deal with peak loads.