Rear screen heater

BackintheFold · 23-12-19, 09:15 AM

When I turn on my rear screen heater, after maybe half a second the fuse (correct rating) blows. This has the disconcerting effect of turning off the dashboard too!

Are there any known weak spots for this please, or do I just follow the cable front to back and look for shorts?
Thanks in advance...

tractor Dave · 23-12-19, 10:44 AM

If you find its the switch I think I have a spare

BackintheFold · 23-12-19, 09:35 PM

Thanks. Switch seems fine.
With any luck I’ll have some time tomorrow. I’ll remove the rear seats and parcel shelf and see if there’s some problem with the wires there. Who knows. I might also find a clue as to why my radio reception is so bad. Maybe the wires have all been sandwiched flat and earthed out.

BackintheFold · 24-12-19, 12:20 PM

Traced problem to the brown 6pin connector by the relay panel.
Had been rewired wrongly and was sending power to earth.

Rewired properly now and all is well. Might be a knock on effect from what I have just disconnected, but that fun can be another day.

There is only one other connector in the circuit, behind the boot trim up by the left hand side rear seat belt reel (thanks Tractor Dave-who usefully has a Quattro in cutaway form...)

23-12-19, 10:44 AM	#2
tractor Dave Senior Member Classic Audi Club Member Join Date: Apr 2018 Location: Wales Posts: 1,157	If you find its the switch I think I have a spare

23-12-19, 09:35 PM	#3
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,171	Thanks. Switch seems fine. With any luck I’ll have some time tomorrow. I’ll remove the rear seats and parcel shelf and see if there’s some problem with the wires there. Who knows. I might also find a clue as to why my radio reception is so bad. Maybe the wires have all been sandwiched flat and earthed out.

24-12-19, 12:20 PM	#4
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,171	Traced problem to the brown 6pin connector by the relay panel. Had been rewired wrongly and was sending power to earth. Rewired properly now and all is well. Might be a knock on effect from what I have just disconnected, but that fun can be another day. There is only one other connector in the circuit, behind the boot trim up by the left hand side rear seat belt reel (thanks Tractor Dave-who usefully has a Quattro in cutaway form...)