Technical X250 elec window problem

[Stu643]

Hi,
I have an intermittent fault on the 2008 type van electric windows. They will work fine sometimes other times it loses power to F45, giving no power to the windows either sides. Anyone seen this before or can give me some pointers were to check.
Many thanks.

 

[rayc]

I thought F45 was the power to the passenger window switch? Is power similarly being lost to F47 & F48? What is happening at T13? The BCM should give an output which switches T13 on pin 86 whenever the ignition is on.

 

[Stu643]

I thought F45 was the power to the passenger window switch? Is power similarly being lost to F47 & F48? What is happening at T13? The BCM should give an output which switches T13 on pin 86 whenever the ignition is on.

Thank you, yes loses power at F47 and 48 as well, I was assuming the feed went to F45 first. Will have a check at T13, as I’ve no diagrams to work off. Strangely it is usually ok with just ignition on, but fails after engine start??

 

[Stu643]

I thought F45 was the power to the passenger window switch? Is power similarly being lost to F47 & F48? What is happening at T13? The BCM should give an output which switches T13 on pin 86 whenever the ignition is on.

Nothing on pin 86 either.

 

[rayc]

Here's the plate.

PS: I'm new to VINs, so not sure if you should hide the full VIN number?

Nothing on pin 86 either.

what do you mean by 'nothing'? It should be battery negative [0v] when ignition is on - have you checked for this? If you take pin 86 to chassis does the relay operate and then the windows? If there is no battery negative at pin 86 when ignition is on it suggests a problem with the BCM [see the drawing I posted previously and this description:]

 

[Stu643]

what do you mean by 'nothing'? It should be battery negative [0v] when ignition is on - have you checked for this? If you take pin 86 to chassis does the relay operate and then the windows? If there is no battery negative at pin 86 when ignition is on it suggests a problem with the BCM [see the drawing I posted previously and this description:]

Sorry, I should have worded that better, I have earth on 86, but no power to the relay. Traced back to bad connection on the 70amp maxi fuse at battery using your diagram. It really helped understand how it all linked. Many thanks.