I got my Window regulator in today, and will be fighting wind & cold tomorrow to install it. As long as I'm in window mode with replacing the regulator & replacing the odd un-tinted rear window, I thought I might as well check into the intermittent operation of the rear windows. What I am facing is if the seat belt chime rings on start up, the rear windows work perfectly, and the front windows will go up & down after the key is turned off. If the seat belt chime isn't working (which is most of the time) the rear windows don't work at all & the fronts do not operate after the key is turned off. Tried to figure this out for a long time, but cant. Ideas?

 

I do know that the window ECU behind the glove box has some issues. Check the sticky for rear window ECU. I guess you received the window in good order?

 

I thought about that, but couldn't find anything that tied the window ECU to the seat belt chime. Will look at it anyway.


Whoops, sorry!! I got the window. Thanks!! Are you parting vehicles, or just downsizing your parts?

 

In the 1996 Model wiring diagram there's a connection between the Windows ECU and the MFU (but only NAS, i.e. North American Specification vehicles). In the 1997 Model wiring diagram there's no such connection. I'm not sure about the exact Model Year change dates and it seems that some details are not always correctly mentioned in the manuals (for example mine has EGR + EDC but interestingly no EGR valve position feedback (only open-loop control by vacuum modulation valve), needless to say that EGR has been blanked). Also some details specific to markets are not necessarily mentioned in the manuals.
Overall the manuals are very useful but I wouldn't trust them blindly before making a modification, it's adviseable to chek how things look really.

 

So what was your problem? Is it fixed?

 

I wouldn't say its as much a problem than an irritation Got the window regulator in easily today & it works perfectly! But as long as I was in window mode today, I was also going to try & figure out why the rear windows only work when the seat belt chimes sounds during vehicle start up. If there's a chime, they work. If there's no chime, the windows are inoperative. I really don't think (or can't find anything that shows) the window ECU has anything to do with the seat belts, so I'm at a loss. But on a more positive note, all the recent running issues seem to be a thing of the past!! Seems that silly MAF o-ring was the root cause of the codes I was receiving.

 

That's great, there is a solder repair for rear windows on the window ecu , also could be a problem with the rear window lockout button if equipped

I know the startup chime you mention mine was intermittent no idea how I fixed it, maybe repairing grounds did it?

 

I didn't check the wiring diagrams in details but an accidental cross short circuit (don't know the exact English term, it means an accidental connection between two circuit parts which are normally not connected together, for example if some wire insulation has been damaged) can cause odd problems (especially accidental connections to the ground).

To find out a good idea would be to carefully check the wire routing in the wiring diagram, especially paying attention to possible accidental short circuits between conductors of the same harness.

I'd also suggest to check if there's no connection between the Windows ECU and the MFU as it is the case with some Discovery I models.

Unfortunately I can't help you much because there are many electrical differences between NAS and non NAS vehicles.