Rear demister problem

[alb]

2004 PA 3.0 V6
Really weird rear window demister problem.
Symptoms - demister doesn't work at all.
-12V at the LHS terminal - indicating supply wiring and fuse all ok.
-Continuity with ground at RHS terminal - indicating system is earthed ok.

12v only last a few mm along *any* track moving from LHS to RHS. Cant see any break in a track anywhere. No continuity between 10mm segments of *any* track *anywhere*.

So what the heck is going on? There doesn't seem to be any voltage getting more than a few mm 'away' from the positive terminal - yet none of the track appear damaged. Even if one or two tracks are damaged - I cant think I've mysteriously damaged 9 tracks at once without even touching them!
Cant help thinking I'm missing something really obvious here. Surely if you use a DMM with the probes 10mm apart on a good track you should get continuity? I don't - is that normal?

Any other ideas - this is doing my head in......

[alb]

rear demister - any thoughts?

any ideas?
I have cleaned the tracks with electrical contact cleaner and they are NON-CONDUCTIVE along their entire length.
Has anyone seen this before? The tracks aren't damaged (to the naked eye) but they DONT conduct. Placing the probes of a DMM even a few mm apart on any of the 9 tracks shows no connectivity. Ive tried all over the window.
Put the probes on the base around the wiring tabs and all good - meter shows a few ohms.
Put probes anywhere on the tracks - nothing.

Has anyone seen this before? Its like the actual material the tracks of made of has 'gone off' ???
I have no explanation ...no tracks are working.

[starjunk]

any ideas?
I have cleaned the tracks with electrical contact cleaner and they are NON-CONDUCTIVE along their entire length.
Has anyone seen this before? The tracks aren't damaged (to the naked eye) but they DONT conduct. Placing the probes of a DMM even a few mm apart on any of the 9 tracks shows no connectivity. Ive tried all over the window.
Put the probes on the base around the wiring tabs and all good - meter shows a few ohms.
Put probes anywhere on the tracks - nothing.

Has anyone seen this before? Its like the actual material the tracks of made of has 'gone off' ???
I have no explanation ...no tracks are working.

I smell a red herring. I suspect the tracks may be coated, except at the base, so you may not be making contact unless you pierce through the track. You're saying you put the probes on the terminals and you see a low resistance. So the tracks are ok. (?) or am I misunderstanding.
Try measuring the current consumed by the element, by removing one of the spade terminals and putting your meter in series on the amps range. (Assuming you can measure 10 or more amps with your meter)
It's possible that you have a damaged wire somewhere along the line, before the element, and that you're getting 12 volts but at very very low current.
The other way to check would be to turn the Dempster (edit: dempster=demister.. Thanks auto-screwup) on, then measure across the 2 spade terminals to see if you still have 12 volts. If this drops significantly upon turning on, then this would confirm a high resistance supply wire in the circuit.
Am I making any sense. Not too sure today, but of a crazy day and I may be rambling but I feel certain that I know what I'm TRYING to say

[KiwiNTPajero]

i can only think that the tracks that you are measuring are not the actual conductive elements but only a "cover"