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Old 10th April 2024, 08:45   #1
YHT
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Default sun roof motor/gearbox

Am trying to get my sunroof to work after several years of being shut. Have removed the motor /gearbox and separated the motor from the gearbox with the controls; the motor works when wired to a battery. Have yet to set up something to try and check the controls. Any one any ideas of how to do it on the bench as I think the roof sliders need freeing up. Also I have checked the fuse The electrical diagrams show a 20A fuse but the motor is marked 1A; anyone tried reducing the amps of the fuse to try and protect the motor in case the slider gets jambed?
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Old 10th April 2024, 10:46   #2
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Quote:
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Am trying to get my sunroof to work after several years of being shut. Have removed the motor /gearbox and separated the motor from the gearbox with the controls; the motor works when wired to a battery. Have yet to set up something to try and check the controls. Any one any ideas of how to do it on the bench as I think the roof sliders need freeing up. Also I have checked the fuse The electrical diagrams show a 20A fuse but the motor is marked 1A; anyone tried reducing the amps of the fuse to try and protect the motor in case the slider gets jambed?
Good point. My sunroof jammed and I guess it must have done for the motor (unsure due to memory cells no lasting to tell me the tale) and I had to get the unit out. I sourced the BMW part (Bosch item I think), renewed the pins and rollers in the slides and all was well.

If you get an answer re the 1A vs 20A issue please ensure you post any result.
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Old 10th April 2024, 11:12   #3
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How did you unjamb the sunrook? Am going to try and shuffle it open by slapping it laterally the right way to get to the slides to clean/grease them while the motor/gearbox is off but if there is a better way.
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Old 10th April 2024, 12:30   #4
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Hello Norman,

The manual says that there's an emergency drive socket in the centre of the circular part of the motor/drive gear casing. You could try that after generously lubricating the runners (silicone spray is effective) and temporarily reassembling.
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The electrical diagrams show a 20A fuse but the motor is marked 1A ...
I suspect that the "1A" you've seen isn't the current rating; it's far too low to be realistic.
The motor is controlled by an ECU with protection software. In any case, I wouldn't advise changing the manufacturer's specified fuse value as it will have been selected to protect the motor anyway.

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Old 11th April 2024, 10:01   #5
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Wot I dune just now.
Tried the motor with the controller atached using a battery but dont think I got the right connections to the power etc. Put the motor/controlled in the car dangling free and connected to ist wiring plug; operated it with the switch and it worked ! Hurrah!!!!

So it must be the sliding bit of the window mechanism so will try lubrication from within at each side where accessible (and hope not too much goes on the roof lining!).
The preoblem with working the sun roof too and from manually is that one has to mount the motor/gearbox so as to engage the roof with the motor and there is a lot of resistance with the motor removed and working that on its own.
Ref the fuse size; dont think reducing the fuse rating can do much harm; if it overloads a smaller fuse it can be replaced; wasnt thinking of putting in a bigger on.
Will try running the motor alone with an ammeter in circuit just to see what current it does take.
Any hints on freeing up the sliding mechanism greatfully received.
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Old 11th April 2024, 10:30   #6
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Ref the fuse size; dont think reducing the fuse rating can do much harm; if it overloads a smaller fuse it can be replaced; wasnt thinking of putting in a bigger on.
But why? What possible reason is there to put the wrong fuse in? The problem seems to be with the slider mechanism - the fuse is a diversion. Rover will have selected 20A for a reason.

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Will try running the motor alone with an ammeter in circuit just to see what current it does take.
Again, why? You will learn nothing useful because that isn't how the motor normally runs. The unloaded current will be a small fraction of the loaded current. And that '1A' label certainly isn't a current rating - it's far too low. As SD1too says, it must be some kind of part identifier or revision number.
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Old 11th April 2024, 14:09   #7
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Thinking of a lower current fuse because many have reported the motor burning out when the sunroof jambs. One would hope the fuse would protect the motor in case of an overload and 20A doesnt seem to do the trick!
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Old 11th April 2024, 14:50   #8
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YHT,

As you have the motor working as you say "dangling" you could put an meter in line and measure the current.


However the current taken when you first switch on the motor when fully insitu would be higher as then you would be starting the motor "fully loaded" so there would be a surge until the back EMF voltage reaches its maximum. Starting current will therefor be much higher than the running current, depends on the motor. it could be 7 times or more.


Hence your stated 20A.
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Old 11th April 2024, 16:41   #9
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Searching through threads generally on line there was asuggestion to remove the motor from the housing - refit the housing and use the allen key to try and move the sunrook too and fro. Removing the motor reduces the drag. Will give it a try.
Still concerned about the number of reports of the motor burning out when the sunroof siezes; seems the 20A fuse does not protect the motor!
Will have a go at measuring motor current on the motor alone just for interest.
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Old 11th April 2024, 16:43   #10
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Searching through threads generally on line there was asuggestion to remove the motor from the housing - refit the housing and use the allen key to try and move the sunrook too and fro. Removing the motor reduces the drag. Will give it a try.
Still concerned about the number of reports of the motor burning out when the sunroof siezes; seems the 20A fuse does not protect the motor!
Will have a go at measuring motor current on the motor alone just for interest.

Does removing the 3 bolts with torx heads either side of the sun roof glass allow the glass to be lifted and better access to the sliding parts of the mechanism?
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