E91 Rear Windscreen Wiper

Discussion in 'Technical Troubles' started by Beemer39, Mar 3, 2019.

  1. Beemer39
    Offline

    Beemer39

    Joined:
    Mar 3, 2019
    Messages:
    2
    Likes Received:
    1
    Ratings:
    +1 / 0 / -0
    I've already searched these forums for a solution without success so apologies if this has been posted before and I couldn't find it.

    The fault with the rear wiper on my 2010 E91 began with a reduced sweep and then failed altogether. YouTube searches showed this to be not uncommon with several videos showing how to replace a seized bearing in the rear window glass. I am OK with replacing that but I have a serious concern that perhaps someone can help with.

    With the rear window glass only raised and the upper cover of the tailgate removed I can see the disk that drives the spindle of the glass mounted unit. When I operate the rear windscreen wiper I would expect that disk to rotate too and fro to operate the wiper - it doesn't. I'm worried that accidental use of the rear wiper while the bearing was seized may have blown the motor as well. So my question is -- does the glass screen have some sort of microswitch that disables the wiper motor when the glass screen is open? If so, where is it and how can I override it to make sure that the wiper motor is still OK before I lash out £92 on a new bearing!

    If there is no microswitch or suchlike, what do I need to do to check if the motor is also dead. A quick look at the fuses in glove compartment looks OK but I'm not sure which specifically relate to the REAR unit - the provided graphics only indicate wipers.

    Also how do you dismantle the rear tailgate covers to get at the motor itself - so far YouTube has failed to provide the answer. I can only get as far as removing the top cover and the carpeted cover that then shows only the mineral wool packing behind the inner door skin. I suspect it's easy when you know how - but I don't!

    Hope somebody can shed some light on this.

    Thanks in advance
    Keith
     
  2. bishbosh
    Offline

    bishbosh WARLORD Site Supporter

    Joined:
    Aug 15, 2015
    Messages:
    1,128
    Likes Received:
    381
    Ratings:
    +592 / 3 / -0
    I had the rear wiper seize on mine. The motors have a surprising amount of torque. When the wiper was moving slowly i lifted the glass hatch and could barely move it by hand.

    Most likely it's the fuse that will have blown rather than the motor. That's what the fuse is designed to do. I'd check that first.

    Also you might be able to get away with overhauling the bearing yourself. The main problem is an o ring that fails - which let's moisture into the spindle which causes it to seize. My first attempt at a repair only lasted a couple of months but the second time I did it I replaced the o ring and never had any trouble again.
     
  3. markyboyt
    Offline

    markyboyt

    Joined:
    Aug 16, 2015
    Messages:
    532
    Likes Received:
    95
    Location:
    Shropshire
    Ratings:
    +167 / 0 / -0
    The microswitch is in the latch on the boot lid, just roll it over with a pick or screwdriver so the car thinks the glass lid is closed and then try again. It will only run with that latch closed.
     
    • Like Like x 1
    • Agree Agree x 1
  4. Beemer39
    Offline

    Beemer39

    Joined:
    Mar 3, 2019
    Messages:
    2
    Likes Received:
    1
    Ratings:
    +1 / 0 / -0
    Sorry for the delay in getting back, I was called away for a few days.

    Bosh bosh - I had checked the fuses and they seemed OK. Noted on the o ring.

    Markyboyt -you were spot on. I pushed a screwdriver into the lock to "close" and the motor turned when operated so I knew I just needed to replace the bearing.

    That job is now done - only took me 20 mins.

    Thanks both for the help

    Keith.
     
    • Like Like x 1
  5. markyboyt
    Offline

    markyboyt

    Joined:
    Aug 16, 2015
    Messages:
    532
    Likes Received:
    95
    Location:
    Shropshire
    Ratings:
    +167 / 0 / -0
    A nice easy fix then, 20 mins is a good time so must have come out fairly easily, they have a habit of welding themselves to the metal sleeve that is part of the window and then they need a bit of drilling to break them free.
     
    • Informative Informative x 1

Share This Page