Sod's law as soon as I get around to finally wiring up the heated windscreen the weather improves and I'm not actually going to be able to see if its working. This got be thinking if there was a way of telling if it was on or not (on the basis that its wired ok).
I cant remember how the Clio's heated rear screen worked but I'm sure in our Scirocco the light in the button stays on for the time that the relay is sending a live to the rear screen.
Would it be as simple as interrupting the lives from the two relays to the two elements with a couple of LEDs or similar, presumably these would have to handle 25A though??
James, I'm beginning to see why you simply just fitted an on/off switch!!