Rear Windscreen Defrosts/Defogs Partially

[yunib]

Hi everyone,

The rear windscreen demister only applies to the top third leaving the rest looking like a sauna took place in the car. Any ideas if it could be a wiring issue? I'm almost certain that it may be the actual heating element lines that may have burnt off but can't seem to find any conductive paint at Halfords or anywhere local for the matter to attempt a fix.

Any input would be appreciated.

[amer6R]

you can see from outside the discoloration of the line that is broken. I think some of the vertical line is broken.

You could try to use a graphite pencil to fill the broken line. But if you wipe the window it will wipe off.

Be careful when you wipe the window. My tab ( the actual) wire ( flat black wire) that clips on to the rear windshield broke. Im not sure how to fix it without removing the windshield.

[SRGTD]

@yunib; If trying @amer6R ‘s graphite pencil repair works, then you could go for a more permanent repair by buying one of rear heater element repair kits. I’ve not tried one so can’t vouch for how effective or successful they are at making a permanent repair but they’re not that expensive, so if your issue is a broken or damaged heating element (sounds very likely if the top section is working), it might be worth trying.

[Mikeso51]

Yunib

If you can find the break in the element, and it’s a small one, you may be able to repair it with conductive paint. If you look on eBay for “conductive paint” there are literally 100s of suppliers with prices starting at just a couple of pounds.

HTH

[yunib]

you can see from outside the discoloration of the line that is broken. I think some of the vertical line is broken.

You could try to use a graphite pencil to fill the broken line. But if you wipe the window it will wipe off.

Be careful when you wipe the window. My tab ( the actual) wire ( flat black wire) that clips on to the rear windshield broke. Im not sure how to fix it without removing the windshield.

Probably easier to break it and get insurance to handle it

[yunib]

Yunib

If you can find the break in the element, and it’s a small one, you may be able to repair it with conductive paint. If you look on eBay for “conductive paint” there are literally 100s of suppliers with prices starting at just a couple of pounds.

HTH

Might have to do that, any suggestions on which one? There seems to be so many variants.

[Mikeso51]

The window heating element has a low resistance and carries a fairly high current, so it’s important that any repair has a low resistance. I would try a silver-based paint. Electrolube make a very good one which I’ve used to repair broken tracks on printed circuit boards. It’s moderately expensive, but has the best chance of working. Best price I could find on eBay was £10 for a small bottle. There are much cheaper Chinese offerings, but pot luck about the quality.