ok ive got a mk1 3 door sierra and found out over christmas that the heated rear screen didnt work and neither did the washer jet which is built into the wiper arm (well im guessing as thats what it looks like) im assuming its not an earth being that the wiper still works, and was wondering if theres a common fault with these? or if anyone knows how i can fix it? as i have no idea where to start, the button for the heated rear screen works fine and changes colour light when on, but doesnt actually heat up the rear screen

 

have ya checked the little loom that goes from the shell to the boot as they wear due to being opened and closed a lot

 

The two problems are not related.
Can you hear the washer pump run ?, may have frozen over cold months and blown the fuse when trying it ?
The HRS, the wires always break inside the insulation,(esp on mk4 escorts!!), so a good probe with a test light, first at the connections on the screen for the live, chances are it is broken inside the insulation from constant opening/shutting movement, but easy fix, just use some heatshrink to seal the wire after fixing instead of tape if you can.
tabetha

 

cant hear any pump run atall, ill check the fuses tomorow and also the wires