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Discussion Starter #1
My rear window heater only partially works.

Only the middle line/filament works. Bit strange as I'm assuming it is comprised of a simple circuit with current flowing through thin wires that heat up.

The heater wire configuration seems to be just one complete circuit so why do the other wires not heat up?:rolleyes:

Any suggestions? (my mechanic was unable to fix it).
 

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Discussion Starter #3
No haven't checked the earth but logically thinking if one is working then it is earthed.
I don't see any broken filaments in the glass. Very bizarre.

Just reading your thread: I'll check these voltages/currents and earth points out.

I'm pretty handy with the DMM. I make my own valve amplifiers!!
 

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Discussion Starter #4
Thinking about this.

If there is insufficient current the current will always take the easiest path with less resistance. In this case the shortest wire (the middle one I guess).

I will check out the earth points and voltages/resistances.
 

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Yes , i have the same problem Only couple of middle lines are working so maybe i too have to check connection because weak current might be the problem.
 

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Im afraid its not as simple as that, you have power to the window as 1 elenent works but have you ever placed any thing large in the car boot that has touched the window (xmas tree) or the like, it will have scratched off a tiny bit of the rear element therefore causing a break on that part of the window. Serveral years ago I bought a magnifiying glass and found 10 breaks in the cuircit which I repaired 9 of them with some electrolite paint (company called granville makes this). its a messy fix but it works. Eventually I bought a new window £80.00p and now it all works.:)
 

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Discussion Starter #7
Iain,

Yes you could be right there. If there is a broken circuit then no current with flow of course.

But isn't it a bit strange that all but the middle one work?
I would expect some not to work randomly if they were accidentally broken.
 

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had this on a lot of cars... and its always breaks in the element, you can repair it as iain says, think halfords also do this conductive paint...
 
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usually get damaged by the window being wiped, often by a ringed finger :(

is an easy enough job to fix though as ian says.

if you can't find the breaks just mask out the lines and paint it all the way across :lol:
 
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