Rear Window Heater Problem

[karachi_kops]

I have a problem with the demister (heater) on the rear window. The problem is that it just doesnt work. When i press the button, it eluminates indicating that its on but nothing happens - the heater doesnt clear the mist on the window.

I have noticed that in one of the lines there is a break but this should not affect the other lines which appear fine .. or am i wrong? Ive been told that its likely to be the rear window which needs replacing but i think this is far fetched.

My car model is 1999 (T reg) Audu A4 1.9 TDi Saloon.

Any ideas,??

:1zhelp:

Karachi Kops

[Arge]

why is it that when i find someone with a similar problem to one that i have, there is no replies to the thread! doh!

basically, i have the same problem with my golf Gti (W reg 2000). i was wondering if you managed to fix it in the end?

[karachi_kops]

hey mate,

no unfortunately i still have this problem. what im having to do is turn the heater on full and within 15 mins the rear windows clear up, however by that time im roasted!!!

Im hoping to get this looked into when the weather clears up. A few ppl have suggested to replace the rear window but we shall see ...

I may take it to an Auto/Elec place and see what they say ... as i have no idea whats causing it!

[Arge]

i've narrowed my fault down to the window, as the wing mirror heaters work and these are turned on with the same switch. i had all of the tailgate trim off yesterday to look at it but i can see no obvious reasons for why it would not be working.

i had the rear washer problem recently (where the pipe comes loose and p*sses fluid into the boot rather than onto the window), so thought that might have caused it. otherwise it could be a break in the wires, but i too find it hard to beleive that the elements would be built in series so that, if one goes, they all fail - if that is the case then the designer wants shooting!!!! ;)

i'll ask around and if i get it working i'll let you know.

[audimad]

Test if there is voltage at the window, with either a multimeter or even a bulb. That way you will know if power makes it to the window. If it does have power then the screen is at fault, if not, could be a relay or switch fault etc

[Zenerdiode]

The mirrors are fused in the switch, the window has a fuse in the fusebox. It will be worth checking the fuse before replacing the window...

[Arge]

audimad & Zenerdiode, thanks for your ideas!

Zenerdiode - I already checked the fuses on mine, and all seems ok.

Audimad - i'll take a look at this later when i get home, and post back on how i get on...

[karachi_kops]

Ive checked the window with a voltage meter, there seems to be continuity however when the demister button is pressed, there is no voltage going to the back, so it most probably will be a fuse. I hope so as tracing the wiring can be troublesome.

Cheers Guys, i'll try and look at this over the weekend :)