Rear heated screen not working

[cocog]

Working through few repairs on my Audi A4 and one outstanding problem I have is the rear heated screen is not working.

The heated mirrors work when heated screen button pressed on centre console.

I have checked the 40A fuse and relay and they are okay. The screen isn't oxidised or any signs of delamination.

I have also checked battery voltage which is 12.3V when static.

Any ideas on what it may be before I start to strip trim out to chase things?

[cliffcoggin]

The points most susceptible to damage are the terminals where the supply connects to the heating element. Have a good look at them first. If possible, test for power at those terminals with a volt meter.

It would also be worth inspecting the wires that pass through a rubber bellows between body and boot lid. They have been known to break with the repeated flexing as the lid is opened.

[cocog]

Okay thanks.

I assume the connections will be behind the trim on right side of boot is that correct?

I had heard there may be some filter module that it goes through as well. There are a few electronic modules in the area around fuse box but not sure what they are. Any idea about them?

[cliffcoggin]

No, I don't know the location of the terminals. If you can see the element it should point to them.

[cocog]

Stripped some bits of to check wiring and got to terminal block for rear heated screen. 12V switching on and off via switch on climate control unit so I can only assume elements have gone on the screen. 12V on strip on screen.

Am I correct in assuming this?

 

If so does anyone have an idea how much replacement rear screen would cost?

[cliffcoggin]

Can you see a break in the element? If so it may be possible to repair it with conductive paint.

https://yourcar.co.uk/best-heated-rear-window-repair-kit/

 

[cocog]

Not really easy to see but looks like may be several breaks in heater element.

Thinking it may be new screen required 

[cliffcoggin]

Your choice of course, but a little pot of paint would cost far less than a new piece of glass. Do let us know the outcome of whatever decision you make.