[gar840]

hi, had a new rear screen fitted last week end and have just found out that heated screen dont work any more

all the wires seem to be in place and the radio works ok is there a some kind of reset that has to be done or maybey some thing else :confused

ta

 

[Vultch]

I'd check the fuse, and i dont know where it lives..

 

[Johnb740]

hi, had a new rear screen fitted last week end and have just found out that heated screen dont work any more

all the wires seem to be in place and the radio works ok is there a some kind of reset that has to be done or maybey some thing else :confused

ta

Common fault of E31's is delamination of the rear winodw that allows moisture ingress that corrodes the rear demister element.

My 850 had this problem and required the replacement of the whole window.

The delamination is signified my a milkyness inside the glass along the sides of the window where it meets the c-pillar.

 

[gar840]

Common fault of E31's is delamination of the rear winodw that allows moisture ingress that corrodes the rear demister element.

My 850 had this problem and required the replacement of the whole window.

The delamination is signified my a milkyness inside the glass along the sides of the window where it meets the c-pillar.

had new screen fitted last week

 

[gar840]

I'd check the fuse, and i dont know where it lives..

i've looked for the fuse too and cant find it :confused

anyone know where its hidding :frown

 

[FND840]

It's the same fuse as the climate control (Air Conditioning) i.e. if the air con is working, it's not likely to be the fuse.

Anyway the fuse is:-
Rating: 7.5 amp
Fuse Number: 21
Location: Front Power Distribution Box.

Hope this helps.



PS Still trying to locate the right 840 Ci Sport to buy.:frown. The search goes on......

 

[Vultch]

Hmmm 7.5 Amps seems a bit low, I dont know the 8 series electrics that well but most cars it in the region of 25A to 40A

Do you have access to a voltmeter or 12 volt bulb spare sidelight or indicator bulb and some wire to see if you can sniff volts when the demist is switched on
gently tease the voltmeter or bulb/wire affair into the connections to the screen

The 7.5 amp fuse might be part of a control circuit that switches a bigger relay

 

[Johnb740]

had new screen fitted last week

Did you check had the fitter reconnected the wires????

Check under the C-pillar trims inside the car.

 

[gar840]

Did you check had the fitter reconnected the wires????

Check under the C-pillar trims inside the car.

yes all wires connected

 

[FND840]

Originally posted by Vultch
The 7.5 amp fuse might be part of a control circuit that switches a bigger relay

That'll be right because you wouldn't want all that power going through a small plastic switch mounted on the centre console. The draw would melt the switch. The switch takes low power and sends a feed to trigger the relay which switches the big "juice" to the HRW. As a comparison Volvo use a 5 Amp fuse for the switch but their HRW is switched through a relay too.

Check the workshop manual Fuse Chart info and also have a look at the wiring diagram for the HRW or "Defogger" as it's called if you need clarification. Fuse- F21, 7.5amps, Front Distribution Box. Have you tried the Air con, as I said if the Air Con is switching then it's not the fuse as both switches take their feed through the same fuse.

 

[migmog]

My rear window could do with being replaced. How much does a new one cost?

 

[gar840]

My rear window could do with being replaced. How much does a new one cost?

if you buy one off the shelf so to speak it will cost you around the £500 mark, i had mine done on insurance just cost the excess of £75

 

[almacg]

if you buy one off the shelf so to speak it will cost you around the £500 mark, i had mine done on insurance just cost the excess of £75

Did you get it fitted by a BMW dealer or one of the windscreen chains?

 

[gar840]

Did you get it fitted by a BMW dealer or one of the windscreen chains?

had it fitted by autoglass

 

[Poorskeleton]

Did you sort out the problem with the defogger because mine doesn't work either? The light comes on on the switch but no actual defogging occurs.

I've checked the fuse and even changed the relay but nada.

 

[gar840]

yes....:thumbsup i stripped the c panels out and found one of the wires was not connected fully :mad