led on switch turning off in on position

Which I forgot to mention But there's another easy way. The LED itself, provided it's 3mm and not the "super bright" type, if you use the car everyday won't make much difference to your battery. What you want is a two pole single throw switch. Small types available from RS, Farnell etc. 4 terminals on back. When switched one way two make contact and the other two break, reverse happens when switched the other way. So when "off" the side with the LED, 2.5 or 12V+ to LED cathode, anode to switch and then ground/(earth)/NEG/(-) is still connected. When switched to "on" window close control is connected, LED circuit opened this LED is off. I believe this switch is also known as an NC +NO.

Here's another way to do what the OP wants.

shezza wrote: Though one pin is set at the + for the led, it is set. Then the other two are in and out. Out doubles up as the earth for the led.

I think you'll find that the "double up" pin is the output to the load and the positive for the LED. I call this pin "Common" below. The pin for the LED is the NEG side of the LED. I call this "Ground" below. Most lighted SPST switches have 3 terminals. Battery, Common, and Ground. The contacts are between Battery and Common. The LED is between Common and Ground. Battery would normally be input, and Common would normally be the switched output. Wire your power Input to the Common terminal. Wire your load to the Battery terminal. Jumper Ground back to Battery terminal with the load. When the switch is open, the LED will be grounded through the load that is now turned off, and it will illuminate. Close the switch, and there is no current flow through the LED (+ to + = no flow), so it goes out. The module has to provide low enough resistance internally between its power input and ground for this to work. I've never tried it, but my hunch is it will work. Test first, before you wrap it all up. So much banter all the time about how complicated it is to do things from you two. Took me less than 30 seconds to figure out how to do what the OP wants.

Davep "congrats" you are the new Howard And I mean it as a compliment.