Grief from a heated rear window

[Pyoor_Kate]

So, I've got this stick on Heated Rear Window I got from Bull Motif a while back. Last summer, I think. Anyway, it's fitted - and it gets power fine...

The first time I switched it on it burned out a section of the element about 1" long. It then promptly stopped working... I'm told I must have fitted it wrong but since it was all stuck to a clean window I find that somewhat... anyway.

While it wasn't working and I'd decided I couldn't be bothered to fix it (intending to get an embedded in the glass one eventually, rather than waste money on an existing disaster) I managed to damage another one of the elements. But then...

A very very nice member of the MMOC has sent me some electrical repair paint to fix it so I filled in the gaps, and it appears to conduct - only now the only segment which demists is that first bit that burned out. It's about 2 inches now I've trimmed off the stuff that'd got very hot when it burned out - and it clears nicely. No matter how long it's on, the rest of the screen remains completely unaffected by the damn thing.

Is it as useless as I think it is (to the point of me thinking of taking it off the screen) or is there something *actually* wrong with it such that I can ask for a replacement? Or... have I somehow done something insanely wrong? Help!?

[rayofleamington]

The bit that demists is the bit that gets hot.
My only guess is that this bit is high resistance meaning it gets hot, but the resistance reduces the current flow too much so that the rest doesn't get hot.
Therefore if you can bridge the bit that gets hot with a low resistance connection, the rest should start working.

(it may then burn out the rest of it as it sounds faulty anyway... but it's worth a try)

[newagetraveller]

You need to reduce the resistance of the repair section by making it thicker and wider.

Use more of the paint to make the repair section wider. Also use several coats of the paint, one on top of the other.

[Nigel2]

I don't know if more paint will do it, the silver paint has no resistance for all practical purposes so the repaired bit has a lower resistance than the rest. It must be made in a series/parallel way for only part of it to work. I bought an old smiths one last year off ebay and that is a continuous loop so if one bit burns out and you bridge it all of it will still work. Sounds like a duff item from new - I should try for a replacement and if they want the old one back tell them to come and unstick it themselves. I cannot see how you have done anything wrong
Nigel

[Pyoor_Kate]

Apparently they're not made anymore, and they were fairly unkeen to offer a refund. At the time I was just so miturated off with the thing and suspected that any replacement would do the same, so I just let it slide. I wish I hadn't now.

[bigginger]

Micturated off - don't you just LOVE the medical speak!

[Multiphonikks]

Aye. She'a almost a nurse now. Sacary huh

Still I have to be nice - hers is the closest I get to a working minor at the moment! I must say though, that that back window is utterly useless - as pointed out by the manic laughing on tht eway to the pool yesterday when I noticed that the tiny bit of clear back window was the only part of the screen doing any good...

[woo]

Do you have any of the aluminium tape left over in the kit? If so I wondered if the aluminium paint might be able to 'glue' each end of a piece of the aluminium tape to bridge the gap. You would need to remove the glue from the inside of the bridging strip where it connected to the original demister.

[Cam]

Sacary huh

It that a combination of Sweet and Scary?

[Pyoor_Kate]

Micturated off - don't you just LOVE the medical speak!

I was quite pleased with that swear avoidance meself. I quite like the term, 's a bit long though.

Do you have any of the aluminium tape left over in the kit? If so I wondered if the aluminium paint might be able to 'glue' each end of a piece of the aluminium tape to bridge the gap. You would need to remove the glue from the inside of the bridging strip where it connected to the original demister.

See, that's what I tried initially but it was a big stinking doesn't work. *but* the genius thought occurs - if I scrape off the paint I put on *grr* and put back in the gaps some of the delightfully useless demister strip from the kit, and then *rejoin* that with the paint, then the thing might work? As a whole? Or burn out a whole new segment.

Ideally I'll get it working just as the weather improves ;-)

[woo]

See, that's what I tried initially but it was a big stinking doesn't work. *but* the genius thought occurs - if I scrape off the paint I put on *grr* and put back in the gaps some of the delightfully useless demister strip from the kit, and then *rejoin* that with the paint, then the thing might work? As a whole? Or burn out a whole new segment.

I thought that was what I was saying

[Pyoor_Kate]

Woo - errr, yes, it was. Sorry, I'd just come back from my shift and was - it would appear - not reading the actual words but what I thought they said.

[bmcecosse]

Throw it away - it's obviously junk. Drive with window open to prevent steamy rear window.

[Pyoor_Kate]

*sigh*

I'll tell you what, you do my 45 minute commute to work with the window wound down at 6:30 in the morning in the middle of winter when it's pouring with rain... and then see how helpful that suggestion is.

[Onne]

probably not a ver refreshing suggestion

[Peetee]

probably not a very refreshing suggestion

Too refreshing I'd say

[bmcecosse]

I do it most mornings (also at ~ 6:30) - in my Mini - in freezing cold Scotland - with window down for exactly the same reason - but it only needs to be a wee bit down, and it can be the passenger side window. And anyway - Minors have the advantage of quarter lights! Open that slightly. You could also just rub a cut potato over the inner surface of the window.

[wanderinstar]

When I get the time I intend cutting a couple of slots in rear shelf about 12" long. A bit like the demister slots under front window. Hopefully the boot seal will not be completly airtight and will aid air extractionand then pull air past rear screen and hopefully demist it.
Sounds good in theory.
Ian.

[bmcecosse]

Get a Traveller - plenty of air leaks at the rear doors - no steamy windows!

[bigginger]

Nah, get a pick-up and you can wipe the rear screen while driving anyway