Hello. A quick question regarding the electric window isolation switch on my 1990 Series III. I am having some sporadic issues with all the windows and the sunroof. I have removed the isolation switch which appears to be in poor shape. The question is: why does it have 3 positions as it is just an on/off switch? How should the switch correctly operate?

Thanks in advance.

Steve

 

I've not seen a 3-way window isolation switch on a Series III but, then again, late model did receive some changes.

How many wires were attached?

Typically the switch simply makes/breaks the ground circuit to the window/sunroof relay

Cheers
DD

 

Hi Doug. Just 2 wires. Here is a pic of the switch. It has up/centre/down positions.

 

If it's just the two wires then it's simply an on/off switch, even if it has three positions

Cheers
DD

 

Cheers Doug. I think the down position allows the operation of all windows, the up position isolates the switches, and the center (neutral) position does one or the other. A bit strange. Anyways, I'll replace the switch and see what happens.

Many thanks,

Steve

 

Hi Doug. Mystery solved. I took apart the switch and found it to be in good condition. After cleaning it, I began to reassemble the switch and I noticed that the rocker portion of the switch can be inserted into the main body of the switch either way. When it is put in one way, the switch will have 2 positions. When inserted the other way, it will give you 3 positions. Mine was simply put in backwards making it a 3 position switch. I now have a fully functional switch with only 2 positions, on or off. Perfect!

Steve

 

Some one has been there before, that PO thing!!!

Carl

 

in the 1990s we used to call that switch a "Valet" switch or a "child-proof" switch.

but I have never seen a 3-position one. Must be a V12 thing.

 

No, it isn't a V12 thing. Every Series III car including the very last 1992 cars had the simple on/off (that is locked/unlocked) switch. The switch in Steve's car has been "improved" in the way that so many of these cars were altered with bad consequences.

 

Gregory,
the funny thing is that this 3-position switch looks identical to the normal 2-position switch.

 

Same switch; can be assembled two different ways. See post #6 !

Cheers
DD

 

That well known car fiddler Charlie Allthumbs gets around a bit, doesn't he ?

 

Jose, I agree, thinking of it as a "child lock" makes sense to me.