What should be the resistance of a heated rear screen?

I’m trying to get my heated rear screen to work on my Elan S3 FHC — it has never been wired up before. The electrical resistance across the screen measures 1860 ohms. This does not make sense to me. Resistance = (voltage squared divided by power), and assuming that the windows consumes about 150 watts then the resistance should be [(12 x 12)/150] ohms, i.e. about one ohm.

Advice greatly appreciated!

John Larkin.

I think they use to draw around 6 to 8 amps from memory have you put a battary on it the resistance could well change after the heat as got the damp out ,would breath on them or put your face to the screen to see if it worked.
Neil

John, I just measured the resistance across my element and it shows 13.9 ohms cold. It has never worked too well with some of the wires making practically no difference, in fact its pretty useless.