It does not seem that the rear window demister is working on my saloon. there are no apparent broken wires on the glass and the No. 4 fuse under the bonnet seems OK, The light on the climate control unit comes on but no sign of wires heating up/ no clearing of the window near wires. Any ideas where to start? thanks
You should take digital multimeter and start testing.:
first - resistance between terminals of demister. (there should be some resistance, otherwise - terminal is broken).
Check one wire which connects to demister for permanent ground.
and other terminal for +12V/battery voltage (when ignition is on and demister is powered on). Is there a battery voltage?
Terminals are on the left and right side of window somewhere in the middle