Window motor only turns one direction.

1999 disco 2. Front right side window was working fine until I had to pull the panel to work on something else and when I put the window down It would not go back up. noticed there seemed to be no power to get it to move up only down. So I pull the regulator and motor Regulator is good condition, motor works but only down. I tried swapping the switches at the console but still the same problem. I can hear clicking behind the dash when I push the switch for down but again when I press for up not even a click. Faulty BCU? Wiring problem? Any help is appreciated as both front windows are out rn and it’s winter in the pnw

Welcome to landyzone regular disabled photos section. worth checking the switch toggles as they can fail over the years. Also check the power to regulator motor okay and to the switch.

saxavordian said:

Welcome to landyzone regular disabled photos section. worth checking the switch toggles as they can fail over the years. Also check the power to regulator motor okay and to the switch.

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any suggestions on how to check the switch toggles other than swapping the wiring between the front window switches which is giving me the same problem just with a different button?

SkeetRover said:

any suggestions on how to check the switch toggles other than swapping the wiring between the front window switches which is giving me the same problem just with a different button?

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Not being an expert on disco mainly Freelander I version at the time. Most toggle switch are fairly standard for rear passenger door and console. If they work okay try a swap.

I’m not a expert on any vehicle, but i know my way around wiring diagrams. Oops u have a BCU involved.

As long as it works one way and the switch was ruled out the problem can be only between the switch and BCU on the up command wire or with the BCU cos the motor's feed is on two wires and the polarity is changing but as you worked there it can be some mechanical restriction which stops the regulator to freely move the glass upwards then the BCU cuts the power like when the window has reached the closed position. The BCU reacts to a higher than normal current draw to cut the feed if you see what i mean

sierrafery said:

As long as it works one way and the switch was ruled out the problem can be only between the switch and BCU on the up command wire or with the BCU cos the motor's feed is on two wires and the polarity is changing but as you worked there it can be some mechanical restriction which stops the regulator to freely move the glass upwards then the BCU cuts the power like when the window has reached the closed position. The BCU reacts to a higher than normal current draw to cut the feed if you see what i mean

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don’t think it’s the BCU in that instance as I have the motor out and connected to nothing so nothing to cause any physical resistance and it still only works going down. Gonna check the wiring from the switch to the BCU when I get more time.

SkeetRover said:

don’t think it’s the BCU in that instance as I have the motor out and connected to nothing so nothing to cause any physical resistance and it still only works going down. Gonna check the wiring from the switch to the BCU when I get more time.

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Then try to make a trick at the motor to swap the wires on it then it should turn the other side when you switch down to rule out a winding issue within it, if it turns the other way with it's wires swapped then the problem is between the switch and BCU or with the BCU

SkeetRover said:

don’t think it’s the BCU in that instance as I have the motor out and connected to nothing so nothing to cause any physical resistance and it still only works going down. Gonna check the wiring from the switch to the BCU when I get more time.

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Do you mean the motor only turns one way , i.e. when taken off the car and you apply twleve volts across the terminals first in one direction then in the other or that when connected to the winding mechanism it only works one way?

Stanleysteamer said:

Do you mean the motor only turns one way , i.e. when taken off the car and you apply twleve volts across the terminals first in one direction then in the other or that when connected to the winding mechanism it only works one way?

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motor is out of the door and disconnected from the regulator but still plugged in through the door wiring. gonna test swapping the power to the leads when I get a chance to rule out the motor being the issue for sure. Thanks for the tips y’all

Ok so after a little more tinkering I’ve ruled out the motor as it works in both directions when 12v directly applied to the leads. Here’s what confuses me. I tested for continuity on the earth wire at the switch as well as the up and down wires at the switch all show no signs of a problem with the wires. Now I’m feeling pretty lost is it possible just a faulty BCU? Or is there something else I’m missing? I’m no expert and have little experience with a multimeter but I feel as though I’ve checked every box that I can think of to narrow down the problem.

Seems very like a BCU fault at this point, unless the circuit between the switch and BCU on the up command is interrupted and to rule that out you must get to the BCU's plug C0660 pin 19 - BU(black/blue) wire like at the switch cos it's hardwired and give earth with a thin wire or needle in it from behind situ, if the motor doesnt react to that you need another BCU and that's complex cos you need programming with dedicated diagnostic tool but if the motor works that way then the wire coming from the switchs is interrupted somewhere. The connector's view is from the contacts side .

Yep, it took me a while to get my mind around the fact that it is the BCU that reverses the polarity, rather than the switch!!
If mine ever went wrong like yours, I'd find a way of rewiring it so the (orA) switch did both ways, and cut out the BCU.
Too much electrickery as usual! Electric windows have been in cars longer than electronix, as we know them today.
So you might have to hold the switch down longer and take you finger off when it gets to the top or the bottom. So what? It's what we have to do for the rear windows in the wife's Pluriel!!

SkeetRover said:

Now I’m feeling pretty lost is it possible just a faulty BCU? Or is there something else I’m missing?

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see above!

Ok gonna try that one last trick sierrafrey mentioned and if that doesn’t work probably gonna just put the window up and unplug it not sure I wanna try to reroute the wiring at this time lol seems so strange that it would randomly stop working all of a sudden. Ah yes joys of owning a LR thanks for the help I learned a lot on this one!

SkeetRover said:

seems so strange that it would randomly stop working all of a sudden. Ah yes joys of owning a LR

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Sadly this is par for the course!
The opening mechanism for my front sunroof "all of a sudden" wouldn't slide back, although it would open. And it is manual!!
We could all list things we just put up with!
I have put up with "for ages" the fact that if I lock the car with the fob, the alarm goes off as I walk away, so I lock it with the key.

Stanleysteamer said:

Sadly this is par for the course!
The opening mechanism for my front sunroof "all of a sudden" wouldn't slide back, although it would open. And it is manual!!
We could all list things we just put up with!
I have put up with "for ages" the fact that if I lock the car with the fob, the alarm goes off as I walk away, so I lock it with the key.

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Way she goes I guess

Stanleysteamer said:

I have put up with "for ages" the fact that if I lock the car with the fob, the alarm goes off as I walk away, so I lock it with the key.

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You can disable the volumetric alarm with diag tool, or unplug the volumetric sensors one by one to see which is fubar then you can replace it or fix it, they used to suffer from corrosion. The door latch was not designed to be used very often with the key it's just for emergency situations and you can end up with a failed latch if you "stress" it too much with the key then things can become very unpleasant or expensive in the unlucky scenario that the fob fails to unlock at the same time.

sierrafery said:

You can disable the volumetric alarm with diag tool, or unplug the volumetric sensors one by one to see which is fubar then you can replace it or fix it, they used to suffer from corrosion. The door latch was not designed to be used very often with the key it's just for emergency situations and you can end up with a failed latch if you "stress" it too much with the key then things can become very unpleasant or expensive in the unlucky scenario that the fob fails to unlock at the same time.

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I will not argue with you, about the weakness of the latch as I know you are pretty much always right, but the offiicial LR way of disabling the volumetric alarm when you have animals in the car is exactly what I do. And considering how many Disco LR owners have dogs I must imagine that they must do it tons.
BUT I take on board what you say and will make efforts to disable the volumetric alarm with my Foxwell.
Yet again something that has stayed on the "to do" list for far too long!

Stanleysteamer said:

but the offiicial LR way of disabling the volumetric alarm when you have animals in the car is exactly what I do

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Off course but IMO the D2 was also not designed especially to carry animals every day all day or to let them in the vehicle over night