Vectra C 2002 rear demister partially working?

[robbocop33]

Bought an old Vectra 2.2 dti elite to run around in while i've taken a major huff with my Megane 225.Cracking old car, everything, and i mean 'everything' works, 46 mpg too, what's not to like for 500 quid! Even the heated leather works after all these years, anyway, now it's getting into damper, colder conditions in the morning when i switch the rear demister only it only clears the top quarter of the screen?
I've tested all the tracks down the window for a live feed with a test light and there's no breaks? Not checked for an actual full 12v reading yet though, would a low voltage supply to the demister make it run out of juice partially down the window? Thanks.

[E-bmw]

Just because each track has 12 volts doesn't mean that the track is good.

Try using your multimeter on ohms & check for continuity across each track.

If you get "OL" on any track, that track is broken.

There is conductive paint you can buy to repair the broken ones but how good it is I have no idea.

[GreenV8S]

E-bmw said:

Try using your multimeter on ohms & check for continuity across each track.

Don't they normally run in parallel? Detecting a broken circuit by measuring the resistance is going to be difficult. Visual inspection might be easier.

[E-bmw]

Well done, you have spotted the mistake of the week, you win a packet of cheezy poofs!

Shoot me now!

[robbocop33]

I used my testlight again, was just a bit too quick while checking each track. Yes tbey all lit but just by luck where i touched them.
Touching each line again but this time in two different places shows 6 of the teack lines are damaged, probably by something on the parcel shelf by previous owners.
Damage is really faint to see, tracks are just 'slightly' lighter at the break points. Liquid repair paint ordered a couple of days ago. Thanks.