Heated rear window

[jonzo]

I couldn't see any other threads on this topic....

On my (fairly) new-to-me E89, only the middle third of the heated rear screen seems to do anything. The top and the bottom stay misted up, which isn't ideal.

Is this a common issue and is there anything that can be done to rectify or would I need to just live with it / replace the screen at what I suspect will be great cost?

 

[B21]

No, not easily, yes, yes and yes

 

[RobbiZ4]

No, not easily, yes, yes and yes?

I've heard about some silver metal paint solutions for broken heating wires/lines.

 

[flybobbie]

My cars never worked, when bought at 3 years old the foil the plug attaches to had pulled off.
Every year i keep meaning to somehow glue a metal contact of sort to try to fix.

Yes there are silver paints, might just be someone has brushed a ring finger and broke the thin foil.

 

[RobbiZ4]

My cars never worked, when bought at 3 years old the foil the plug attaches to had pulled off.

Are you talking about the connectors soldered directly onto the rear windows of our E89's?


On this window the connector was teared off due to a former repair attempt by a garage.

 

[jonzo]

Okay, looks like they're pretty fragile then.

I'll have a look at the track and check for obvious damage / breaks.

It's not the end of the world but if it can be fixed then that would be good.

 

[RobbiZ4]

Okay, looks like they're pretty fragile then.

Yes, they are!

Inbetween I always spray these contacts with silicone spray and wait 5 minutes.
Then I start to remove the plug very, very carefully with both hands: with one hand I keep the metal part firmly on the window, with the other hand I wiggle the plug and pull it off. May take a (1) minute!!

I you simply pull on the connector, the metal tongue will be teared off from the window.

...if it can be fixed then that would be good.

Yes, it can.

..., only the middle third of the heated rear screen seems to do anything. The top and the bottom stay misted up, which isn't ideal.

But this effect can't be sourced by a teared off contact.

 

[flybobbie]

Yes my car has detached just like the photos.
Was already broke when i purchased the car
I think there might be elect some kind of electrical conductive resin to stick back in place.

Only thing i can fins is this,
https://www.ebay.co.uk/itm/183534580706?_skw=electrically+conductive+glue&itmmeta=01JEG12CKM7T6YK616DZEZ132P&hash=item2abb8373e2:g:KfAAAOSwRbJb6z3j&itmprp=enc%3AAQAJAAAA8HoV3kP08IDx%2BKZ9MfhVJKmIt%2F00sbYQj%2BqVTlJJ7P3Ki6HUqrkHlK6BRUQUQZCpOKn5ldMuExcC8oMcbgKp8Nw1k2KVfuqNWwC04rt0TUZrQQuWdJqGpS42xVJ9u61REluyn%2FAm0AfuZruFTWhctQNhi%2FMko%2BBVo3YY95F%2Fqxn94qV3hTfmK2x2mVxUoMraLHyAfFJJQdjgIf1nNXgyKmENhYZ08fKYv5kYKEzcwtjOYOXy3kiXGEqZQS%2BzS%2F9cLAHQiT%2FQObUhTbTs0mZuvcWXeRaz9AytedT%2FSUS5hJDYvrDKyO1GLmKqFKSpf%2FqgcA%3D%3D%7Ctkp%3ABFBM-MmJgfRk

To make a electrical contact then hold in place by foil tape.

 

[RobbiZ4]

I can re-weld these contact tounges after dismanteling the rear roof shells.

Take a temp.regulated heatgun, put a tiny 5 mm nozzle on it, turn the temperature up to 500°C, grab the contact tongue with a combination pliers, heat the tongue up, fix it against it's intended position on the rear window lying upside down and put carefully some solder on several welding points around it.

Stay calm and work with extreme caution, always aware that you are playing around with a 500°C hot tool on a big window!! Indeed no job for beginners. :rofl:

You eBay link:
"Note: Not suitable for windscreen wire repair."

 

[matsmith749]

...or replace the rear screen.

 

[RobbiZ4]

...or replace the rear screen.

:rofl: Ok, that's the 2nd most expensive solution.
AFAIK, the rear roof shell has to be taken off for this task as well. :driving:

The most expensive solution will be replacing the E89 with another car.

 

[flybobbie]

Yes years ago i tried soldering back on, no luck, not hot enough, but these days solder just seems rubbish quality.
Don't even mention silver solder!

 

[RobbiZ4]

Yes years ago i tried soldering back on, no luck, not hot enough, ...

I did various temperature tests on old windows before I dared to solder the rear Z4 window with up to 500°C. It's a risky adventure of course.

 

[flybobbie]

Solder paste and plenty of flux as used in attaching chips might be better solution.
https://www.ebay.co.uk/itm/285155169823?_skw=solder+paste&itmmeta=01JEGZGS2B3XYRQQY8KM13Q5FH&hash=item426492961f:g:hwQAAOSwNjRj9MQQ&itmprp=enc%3AAQAJAAAA8HoV3kP08IDx%2BKZ9MfhVJKkpTYtrsKbMh4JAQFwICP9qo41WFti7TN0tbMzr47G8K6D6oQpfN2KxSy02qJWIp1P1NS%2BJMlj4HesAjrDHuZCVIgZUJcxp6FLpueISv6f%2FwHBTZM7hWm6ZpPw%2FTAUeTPiymruTgLbAN0UZXDlbg%2FapFmFfdTmyh%2BJKM1G%2BnKgu7YeDNmJJ8pHDVOTCrFPQ%2FFFZ9y80Xvee3MZYn5AdSUflaF%2FttGjPAyqfnYb1tlRMCrZETqUbo0PWiBNYoE6LJugNuSl1eh6QX0PJoILH4bNGmdg%2FkCC51mRuCm7A6BrIeA%3D%3D%7Ctkp%3ABFBMppHDn_Rk

 

[RobbiZ4]

Yes years ago i tried soldering back on, no luck, not hot enough, ...

I did various temperature tests on old windows before I dared to solder the rear Z4 window with up to 500°C. It's a risky adventure of course.

Well, AFAIK that also has to be heated.
The main problem is, that this big window is a giant heatsink, which fights against all warming up attempts. :fuelfire:

 

[flybobbie]

Comes in various melting points and being a powder might be easier to melt than solid core.
With a flux it's already sticking to parts without glass removal.

 

[flybobbie]

Well ordered the 138 degree paste, give it a go.

 

[ARCS]

Yes my car has detached just like the photos.
Was already broke when i purchased the car
I think there might be elect some kind of electrical conductive resin to stick back in place.

Only thing i can fins is this,
https://www.ebay.co.uk/itm/183534580706?_skw=electrically+conductive+glue&itmmeta=01JEG12CKM7T6YK616DZEZ132P&hash=item2abb8373e2:g:KfAAAOSwRbJb6z3j&itmprp=enc%3AAQAJAAAA8HoV3kP08IDx%2BKZ9MfhVJKmIt%2F00sbYQj%2BqVTlJJ7P3Ki6HUqrkHlK6BRUQUQZCpOKn5ldMuExcC8oMcbgKp8Nw1k2KVfuqNWwC04rt0TUZrQQuWdJqGpS42xVJ9u61REluyn%2FAm0AfuZruFTWhctQNhi%2FMko%2BBVo3YY95F%2Fqxn94qV3hTfmK2x2mVxUoMraLHyAfFJJQdjgIf1nNXgyKmENhYZ08fKYv5kYKEzcwtjOYOXy3kiXGEqZQS%2BzS%2F9cLAHQiT%2FQObUhTbTs0mZuvcWXeRaz9AytedT%2FSUS5hJDYvrDKyO1GLmKqFKSpf%2FqgcA%3D%3D%7Ctkp%3ABFBM-MmJgfRk

To make a electrical contact then hold in place by foil tape.

I used this stuff, then some conductive paint once stuck.

https://amzn.eu/d/eB43lbX