Electric window probs

The Mad Hat Man · Jul 9, 2015

Anyone got a circuit diagram for a Disco1 300TDi window ECU & wiring. Passenger window wont move down. I don't think its the window ecu as i think that only effects rear windows, so any help appreciated. I have checked switch and door. Everything is connected as it should be. Volts on door connector when switch is pressed "up", but not when pressed "down". Swapped switch - no difference.
My understanding was switch just reverses polarity of wires, so I am at a bit of a loss as to why power to motor is ok when when motor trying to go up, but not down, unless the switch doesn't control the motor directly?????
I have Rave and the 300tdi supplement. Also the paper manuals and they don't seem to cover the "ECU'd" version

Dippypud · Jul 9, 2015

Have you tried direct feeding the motor in case it's just a duff wire ?

The Mad Hat Man · Jul 9, 2015

Dippypud said:
Have you tried direct feeding the motor in case it's just a duff wire ?

motor only uses 2 wires, so if there is volts and ground in one direction, it proves wires are ok. my understanding was the the switch reverses polarity, but it seems not unless the ECU is between the switch and the motor - or in the supply to the switch?????

Dippypud · Jul 9, 2015

The Mad Hat Man said:
motor only uses 2 wires, so if there is volts and ground in one direction, it proves wires are ok. my understanding was the the switch reverses polarity, but it seems not unless the ECU is between the switch and the motor - or in the supply to the switch?????

Stick a light bulb on it .....

Can you hear it 'clicking' ? the ECU I mean ... I seem to think they should ...

I can only find a D2 diag, (the BCU), from 2003, that has two wires to the switch as well....

The Mad Hat Man · Jul 9, 2015

Dippypud said:
Stick a light bulb on it .....

Can you hear it 'clicking' ? the ECU I mean ... I seem to think they should ...

I thought the relays only operated on the rear windows, not the front - hence my confusion....

Dippypud · Jul 9, 2015

The Mad Hat Man said:
I thought the relays only operated on the rear windows, not the front - hence my confusion....

Your confused ?

I dunt know nuffin'

Dippypud · Jul 9, 2015

The rear windows don't use relays or the BCU, they're switched directly by the window switches, which are double pole changeover switches -

or so I'm told now

The Mad Hat Man · Jul 9, 2015

so whats the ecu for - dont forget this is a D1, not a D2 - i thins they is different.

Dippypud · Jul 9, 2015

Have you got the ECU out yet ?

Have you opened it ?

Does it look like this ?

The Mad Hat Man · Jul 9, 2015

no i havent - thats the next stage. hopefully with a wiring diagram

Dippypud · Jul 9, 2015

Right !!!

Found this;

You can test for failure of the ECU in rear window power issues, before removing it, by testing for power on the input and output pins of the rear window circuits.

Once you’ve located the windows ECU, note that there are two connectors. The connector with 10 pins is C287, it is used for control signals.
The connector with 8 pins is C288. C288 has heavier gauge wires and is used to deliver power to the window circuits.

1. Input power for the rear window circuits is received on pin 8 of C288 (purple wire next to the white wire).
If you don’t see 12V on pin 8, check the rear power window fuse (F2 of Satellite Fuse Box 2).

2, Pin 3 of C287 (green wire) is a control signal indicating that the ignition switch is on.
You should see 12V on this pin when the ignition switch is on.

3. Output power for the rear windows is delivered on pin 4 of C288 (white wire).
When pin 8 of C288 and pin 3 of C287 are both at 12V, you should see 12V on pin 4 of C288.

If you are not seeing 12V on pin 4, then you probably have a failure in the ECU on the solder joint highlighted in the article.

If pin 4 of C288 is producing a 12V output, the problem is probably in the wiring or switches, not the ECU.

The Mad Hat Man · Jul 9, 2015

thats brill, Dipps - but how does that help me with a ns FRONT window?

discool · Jul 9, 2015

There is a diagram in the Haynes manual which looks okay I'll have a look at it tomorrow that will tell me how the windows function, also I may be able to scan the page and attach to post if u don't have a Haynes.

The Mad Hat Man · Jul 9, 2015

discool said:
There is a diagram in the Haynes manual which looks okay I'll have a look at it tomorrow that will tell me how the windows function, also I may be able to scan the page and attach to post if u don't have a Haynes.

My Haynes only shows 5 pin switches, but my car has 6 pins. so I couldnt use that - deffo wired differently too.

Dippypud · Jul 9, 2015

The Mad Hat Man said:
thats brill, Dipps - but how does that help me with a ns FRONT window?

Shaddup

The Mad Hat Man · Jul 9, 2015

Dippypud said:
Shaddup

I DO appreciate the ideas tho :hug:

Dippypud · Jul 9, 2015

The Mad Hat Man said:
I DO appreciate the ideas tho :hug:

You have checked the 30A fuse haven't you ?

Yoyodyne · Jul 9, 2015

Are you sure it's an electrical fault? All the probs I've had with my and RRC and current Disco windows have all been mechanical. Scissor mechanism, motor drive on the big coggy like bit etc. Pull the door cards off and make sure everything is running freely and the glass is not jamming

The Mad Hat Man · Jul 9, 2015

Dippypud said:
You have checked the 30A fuse haven't you ?

yes - and 3 out of 4 windows work fine.... and the 4th will come up, just not down. which makes me think its something to do with the polarity switching on that window.

Dippypud · Jul 9, 2015

The Mad Hat Man said:
yes - and 3 out of 4 windows work fine.... and the 4th will come up, just not down. which makes me think its something to do with the polarity switching on that window.

Try the 'good' motor in the window, it'll tell you if it's wiring/ECU or motor ....

Electric window probs

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