GTV Rear screen demister fix.

[SimonT]

Originally Posted by jus

How long should the rear demister stay on for before it cuts off?

Its further back in the thread somewhere - 20 mins??

[GCPV6]

Can you tell me what the fuse for the demister looks like? Is it one of the big square black ones with flat pins sticking out of it, or is it one of the smaller coloured plastic ones? I don't have an owners handbook and there is no guidance as to what's what in the fuse box itself! And which fuse is it? (i.e what position is it in?)

Thanks

[SimonT]

The big square black things are relays. Its a 30A fuse (the fuses are the little coloured things) which is red (with 30A on it!) next to the heated rear window symbol, third in from the end. If any are melted (but perhaps still working) that will be it. Its capable of getting hot enough to melt the plastic and even the fuseboard but not burn out itself!!

Try doing an internet search for the manual - I bet its out there somewhere. Or even just search this site.

[jus]

Originally Posted by GCPV6

Can you tell me what the fuse for the demister looks like? Is it one of the big square black ones with flat pins sticking out of it, or is it one of the smaller coloured plastic ones? I don't have an owners handbook and there is no guidance as to what's what in the fuse box itself! And which fuse is it? (i.e what position is it in?)

Thanks

Would u like me to scan in and send you the pages on fuses in my manual. As a pdf.

[Nige005]

Post # 9 in the link MAY help, it's from the manual.

http://www.alfaowner.com/Forum/alfa-...ont-start.html (air bag warning: car won't start)

[GCPV6]

Originally Posted by jus

Would u like me to scan in and send you the pages on fuses in my manual. As a pdf.

Yes please! That would be really helpful. It's a pretty neck breaking job getting down in to the footwell trying to look at the fuses and nothing seems to be marked up (no helpful diagram on the back of the fuse box cover either).

[jus]

Originally Posted by Nige005

Post # 9 in the link MAY help, it's from the manual.

http://www.alfaowner.com/Forum/alfa-...ont-start.html (air bag warning: car won't start)

Was this directed at GCPV6? does this have the pages I offered to scan?

[Scott_Goozee]

I was reading this feeling smug as mine hadn't broken yet but the bloody thing stopped working the other day and I have just looked at the fuse box and it is badly melted

My dad says that it's possible to re wire it so it doesn't go through that fuse terminal as I doubt i'll be able to get a new fuse in or the old one out at that. Has anyone tred this and put an in line fuse next to the fuse box??

[Stixy]

Originally Posted by Scott_Goozee

I was reading this feeling smug as mine hadn't broken yet but the bloody thing stopped working the other day and I have just looked at the fuse box and it is badly melted

My dad says that it's possible to re wire it so it doesn't go through that fuse terminal as I doubt i'll be able to get a new fuse in or the old one out at that. Has anyone tred this and put an in line fuse next to the fuse box??

Just read post number 1 The fix is easy to do,took me about an hour to do.

[GCPV6]

Ok, so I got down and dirty with my fuse box today and.........there is only one 30amp fuse in the box. It is yellow not red, and it hasn't blown or melted. But, the demister doesn't work although the light comes on in the switch. There is no smell of burning and nothing else has melted Any ideas gratefully received!!! Anyone????

[misterchase]

Originally Posted by GCPV6

Ok, so I got down and dirty with my fuse box today and.........there is only one 30amp fuse in the box. It is yellow not red, and it hasn't blown or melted. But, the demister doesn't work although the light comes on in the switch. There is no smell of burning and nothing else has melted Any ideas gratefully received!!! Anyone????

Generally speaking the 30a fuses are light or dark green. red ones are 10 amp, yellow are 20.

It is possible (and happens often) that the fuse has melted and fallen out completely. if you have an empty slot for a fuse in the centre column of fuses then that may be the case. There is definitely a rear screen symbol adjacent to the fuse slot.

The led on the switch works from a different circuit than the demister. The switch 'talks' to a control module that energises the rear window and heated mirrors for a set period of time.

Incidentally I have done the fix detailed in this thread and I still melt the 30 amp fuses at the new relay in the boot. Ho Hum.

Good luck
MC

[stoyce]

Originally Posted by GCPV6

the demister doesn't work although the light comes on in the switch. There is no smell of burning and nothing else has melted Any ideas gratefully received!!! Anyone????

You need to check with a multimeter if the signal is coming out from the switch to the fuse. Process of elimination.

[stoyce]

Originally Posted by A D Diagnostics

Incidentally I have done the fix detailed in this thread and I still melt the 30 amp fuses at the new relay in the boot. Ho Hum.

Good luck
MC

Does the demister work for a while, then melt the fuse? Have you used the right gauge wire?
Is there a short from the fuse to the window element?

Check all these first.

[misterchase]

Originally Posted by stoyce

Does the demister work for a while, then melt the fuse? Have you used the right gauge wire?
Is there a short from the fuse to the window element?

Check all these first.

The demister works perfectly, over the course of 3-4months over xmas it gradually melted the fuse covering. I've used very thick wiring, there is no short circuit.

Cheers
MC

[stoyce]

Originally Posted by A D Diagnostics

The demister works perfectly, over the course of 3-4months over xmas it gradually melted the fuse covering. I've used very thick wiring, there is no short circuit.

Cheers
MC

Ok, it sounds like we may need to beef up the fuse holder. I'll see if there are any heavy duty ones available.

Cheers
Simon

[CraigMans]

Ok so my fuse has burnt a bit of a hole in my fuse board, but everything is still working around it! How do I check if the timer is knackered? Is it in the footwell of the passenger side and if so has anyone got a picture of the positioning of it please?

Thanks in advance,

Craig.

[panadero]

Hi all,

Just a warning of the dangers of ignoring the burning smell from using the rear demister. Thanks to to this post I no longer have to worry (so much) about my Alfa burning down!

Take heed!

Cheers.

[stoyce]

Originally Posted by CraigMans

How do I check if the timer is knackered? Is it in the footwell of the passenger side and if so has anyone got a picture of the positioning of it please?

Thanks in advance,

Craig.

You can check the timer with a test light and a clock. Connect it to the Br/Wh wire, with the engine running, the light should stay illuminated for approx 20 mins.

The 'integrated services control unit' (timer) should be in the passanger foot well. It may well be under the dash by the fuse board on some. I don't have a photo.

[Stixy]

Originally Posted by stoyce

The 'integrated services control unit' (timer) should be in the passanger foot well. It may well be under the dash by the fuse board on some. I don't have a photo.

This unit lives behind the glovebox on RHD cars and is purple in colour.

[CraigMans]

Thanks guys, I appreciate the input. The problem I have is that when I plug a fuse back in it gets pretty bloody hot straight away! I dare not leave another fuse in to long! Any idea what I should do?

Thanks again by the way.

[stoyce]

Guys.

If your at all struggling with this, please please please seek advice from an auto electrician.

It is an easy fix and a qualified electrician will find this easy to carry out and make all the right checks.

[CraigMans]

I have just spent £1200 on a repair £900 of that in labour! I didn't expect to have to pay out. My baby daughter was born a week ago! I can't really afford the price of an auto electritian. If I get as much info as I can, I will be able to do it myself I am sure.

But thanks anyway.

[stoyce]

Craigmans,
I don't mean to sound condescending to anyone in my previous post, but as a matter of safety for you it is highly important that you understand what your doing with auto electrics.

Ok, do you have a test lamp or multimeter?
Have you fitted the new relay and fuse in the back?
Is the existing fusebox in good order?

You can test the timer with either a test lamp or multimeter. The engine must be running (so the battery voltage doesn't drop off), and the original fuse removed from the fusebox. Switch on the rear screen demister and probe the live terminal of the fuse holder with the test lamp (one of the fuse terminals will become live when the switch is on).
Keep the probe on and check with a watch / clock that the timer switches off after approx 20 mins, give or take 5 mins.

If it stays on continuously, then you need to source another control unit.

Once your happy it works, fit a new 5A fuse in the fusebox and check the signal now goes to the back of the car, supplying the new relay. If it doesn't, there is a connection either behind the glove box, or under the passenger footwell carpet. This connection can burn out also (on the br/wh wire).

When your happy with that, make sure you fit a 30A fuse fitted in the new fuse holder in the back, and all should be good!

Regards
Simon

[CraigMans]

Thanks Stoyce,

I didn't mean to sound offended in my last post! I realise how important it is and realise that its not good to bite off more than you can chew. So thanks very much for this. I will have a look at it at the weekend. I really appreciate the help.

Craig.

[stoyce]

Originally Posted by CraigMans

Thanks Stoyce,

I didn't mean to sound offended in my last post! I realise how important it is and realise that its not good to bite off more than you can chew. So thanks very much for this. I will have a look at it at the weekend. I really appreciate the help.

Craig.

No prob's Craig - just trying to stress a safety issue

Good luck, and shout if you need more help.

Cheers
Simon