The Discovery II only uses the BCU to control the front windows (the rear windows are switched directly by the switches), isn't it ?
Nigel-S
soft and furry
I've removed the mechanism that lifts/lowers the drivers window and propped up the window with a piece of timber. I'm away all day tomorrow (Sunday) so won't get the chance to investigate until Monday. Hopefully nothing too serious.
Nigel-S
soft and furry
Here's as far as I've got. The motor works absolutely fine on the bench, up and down no problem at all. Checking the connector in the door there's no power getting to the motor, also no power (as far as I can ascertain) to the up/down switches.
Fiddled around with the BCU and can't find anything loose or damaged, still getting a click when the up/down switch is pressed.
What I did find to be odd is that next to the (in car) fuses there is provision for several relays, the one with the window image has no relay in it
. Yet the windows have worked fine up to a couple of days ago, now I'm totally confused
Fiddled around with the BCU and can't find anything loose or damaged, still getting a click when the up/down switch is pressed.
What I did find to be odd is that next to the (in car) fuses there is provision for several relays, the one with the window image has no relay in it
. Yet the windows have worked fine up to a couple of days ago, now I'm totally confused 
sierrafery
Well-Known Member
are you sure that all the involved fuses are OK? ... and everything else except the windows is working... that's important so double check all the systems(wipers, washers, heated screens, seats, etc)
sierrafery
Well-Known Member
take that relay from bottom and put it above to see what happens, maybe somebody made a joke on you or something cos it's not supposed to be a relay there on a td5(it's only for V8 for ignition) but it should be one where your's is missing... or there's some hystorical bodge in the fusebox which has finally failed
Nigel-S
soft and furry
I've moved the bottom relay up and now the rear windows are working, so that's some good progress made
.
Nigel-S
soft and furry
I've checked the one's you suggest and they are fine, there is provision for 4 more relays which I assume to be for things like heated seats, electric sunroof etc. Since the front windows stopped working when I was driving, I know that nothing has been meddled with. A couple of weeks ago I fitted a new gearbox so will remove the centre consol and see if I've damaged any wires.
sierrafery
Well-Known Member
no relays in the engine bay involved in the front windows operation, i'm wondering though how that rear window lift relay ended up in the V8's ignition position ??
Nigel-S
soft and furry
The vehicle was main dealer serviced up to November last year, I bought it in June this year. I've had all sorts of things go wrong with it, the last thing was the alarm didn't work properly (random alarm going off, engine disabled etc). I finally found out that the 'main dealer' had fitted the wrong reciever (the one in the roof), I fitted the correct reciever and all worked perfectly after that. Going by the standard of servicing I'm not really surprised the relay ended up in the wrong place
Soon as I've removed the central consol this afternoon and checked for damaged wires, I'll report back. Thanks guys for your help
Nigel-S
soft and furry
Right chaps, I've taken the centre consul out and thoroughly checked all the wiring for any nicks that might have happened during the gearbox change, I've found the wiring to be intact with no damage. From here I'm suspecting something to be wrong between the consol and the BCU, not easy to get at the wiring between these 2 points, but it's getting to look like the BCU is suspect? I hope not........ I'm fast running out of money
gemsdad
NOT BOTHERED.
Found this one on fleabay.171876332259Right chaps, I've taken the centre consul out and thoroughly checked all the wiring for any nicks that might have happened during the gearbox change, I've found the wiring to be intact with no damage. From here I'm suspecting something to be wrong between the consol and the BCU, not easy to get at the wiring between these 2 points, but it's getting to look like the BCU is suspect? I hope not........ I'm fast running out of money
sierrafery
Well-Known Member
i'll check the diagram later and i'll tell you what measurement to make to get closer to an answer... the best would be if you could plug in a tester to run circuit test for the front windows... that would reveal if the problem is before or after the BCU
sierrafery
Well-Known Member
on a second thought if you hear the click it means the BCU gets the signal from the switch so see RAVE - Electrical library - connector views - earth header C0017 pin 7 and check if it's no corrosion there or something cos that's the earth which the BCU is switching for front windows and that area is exposed to water ingress quite often
Nigel-S
soft and furry
Thanks John, this is located just a few miles down the road from me. Bought a few bits and pieces from them in the past so worth a visit if it's the BCU at fault.
Nigel-S
soft and furry
I'll check that first thing tomorrow morning, as you say that area can be subject to water ingress and it's quite possible corrosion is playing it's part. Will take a look at RAVE and print off the appropriate page. Thank you for your valuable help, it's much appreciated
sierrafery
Well-Known Member
welcome, i kinda doubt that the BCU to be faulty only for the front windows operation, it usually gives you much more trouble but everything is possible... if the earth is good meaasure if the BCU has feed with ignition on at C0664 pin 7 and C0660 pins 1 and 13 then put voltmeter across C0664 pins 1 and 4 and give any command with the front LH window switch to see if you get any activity... according to the results we'll speak again, good luck
