Heated Rear Window

[simonriley11]

How can I check if my hrw is working without it being iced or fogged up. My car has an alternator and voltmeter, so no obvious discharge as seen with an ammeter. I suspect it's not working as the headlights and heater fan do not dim/slow down when the engine is at tickover and I switch the hrw on. Is it possible to measure the resistance across the element maybe? Also is there another fuse box to check other than the 4 in the dash, my car is a UK spec 1973 S130/5.

[types26/36]

You should be able to feel the screen getting warm but maybe not as its so pathetic (or at least mine is)
Check with an ohmmeter if you have continuity between each end of the element, then check with a volt meter if you have a 12volt feed with the switch on. Lastly check it the other wire goes to ground (earth) you can check that with the ohmmeter (continuity to ground)
Brian