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Thread: Weird electrical problem - windows + wiper - solved

  1. #1
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    Weird electrical problem - windows + wiper - solved

    Have a weird electrical problem with my car. All windows and the wipers will stop functioning roughly 10 minutes into a drive. Car needs to be shut down for at least half an hour before they start working again. Heat might be a factor because if I park in a hot environment or on a hot day, they don't work from the start. This behaviour has been consistent for months.

    Have checked the fuses they are good. Changed general and relay module, no effect. Changed wiper stalk, no change. Exact same behaviour. Might be a wiring issue, something frayed somewhere. Dread checking on that. But anyone know where to start or what could actually be wrong, would help narrow down. Thanks.

    Alan

  2. #2
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    It is the fusible link. I bet your seats do not work either. It is in located near the battery under the rear seat. Look it up and you will get a good pic.

    Andy

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    Check the fusible link which goes from battery + pole inline to the fuse box under rear seat driver side. I assume the fusible link has a hair crack which works sometimes depending on temperature.
    Typical Failure syndromes:
    • Intermittent simultaneous falure of wipers, sunroof, windows, central locking, radio...
    • No power, like if the battery was dead

    http://www.bmwe34.net/E34main/Mainte...sible_link.jpg
    first 2 pics os the fusible link which goes to engine bay e-box, 3rd pic is the fusible link for the rear fuse box, and that controls all the stuff which is not working on yr car via the GM http://www.bimmerboard.com/forums/posts/377728/
    Last edited by shogun; 10-12-2018 at 10:38 PM.
    Shogun tricks and tips for the E32 series are HERE!

  4. #4
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    Oh if it was only as simple as that! But please question I have never had any current cut off issues in any form intermittent or otherwise that had, anything to do with the fusible link. Can it still be responsible for this issue?

  5. #5
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    Oh if it was only as simple as that then there is a godt!

    But please a question I have never had any current cut off issues in any form intermittent or otherwise that had, anything to do with the fusible link. Can it still be responsible for this issue?

  6. #6
    moroza's Avatar
    moroza is offline MORΩN ΛABIA BMW CCA Member
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    Quote Originally Posted by alang1990 View Post
    I have never had any current cut off issues in any form intermittent or otherwise that had, anything to do with the fusible link.
    Yes you have; the issues you describe are current being cut off. In this case (probably) because of hairline cracks in the fusible links. Common E34 problem, cheap and easy to fix.

  7. #7
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    Quote Originally Posted by shogun View Post
    3rd pic is the fusible link for the rear fuse box, and that controls all the stuff which is not working on yr car via the GM http://www.bimmerboard.com/forums/posts/377728/

    So there is a SECOND fusible link, that ONLY controls GM related stuff? I didn't know that. That makes a lot of sense. It is a current cut off as moroza point out. I'll check that along with my driveline later asap. Thanks !!

  8. #8
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    Yes, there are TWO!

    This fusible link B controls all stuff = central chassis electronics including the GM under the rear seat. But check it in detail, the cracks are often difficult to find, sometimes under the bolts/rivets.
    Pics and explanations are on my website in a pdf file.
    ---------------------------------------------------------------------------
    When you have probs with the engine: The other one = fusible link A goes to the engine bay , fusible Link A can also go intermittent and kill power to the the DME box. You can conveniently check this at your D100 Diagnostic Connector, pin 14. The voltage should be 12V at all times. If it is low when cranking, then Fusible A is your problem.
    Shogun tricks and tips for the E32 series are HERE!

  9. #9
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    Well well. Another day and another good morning for the old warhorse. No make that a great morning.

    Here's why :


    Fusible Link A1.jpeg

    Fusible Link A2.jpeg



    The problem was the fusible link, but not link B which controls the cabin electricals. It was Link A which is supposed to kill the car itself if damaged. Apparently the fuse B for link B is in the Link A box and Fuse A for Link A is in the Link B box, There seems to be some parallel wiring in the fusible link boxes that makes it work this way.

    So I inspected the link and it seemed ok. Put a wire across it and the windows and wipers suddenly started working - the first picture above. Then I unscrewed a bolt and the link broke entirely on its own - second picture above.

    Removed it and ended up snapping it into 3 easily. It was way too brittle for a 90A fuse. Since its the fuse for Link B the engine started and ran normally. Decided not to use a wire to short the bolts for the broken fusible link - don't want any more October surprises..

    Two fusible links on order now. Thanks to shogun for pointing the way. Amazing how something I struggled with for nearly a year was solved just like that.


    Alan
    Last edited by alang1990; 10-14-2018 at 09:40 AM.

  10. #10
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    In pic 1 that fusible link is not installed correctly. It looks like it was already broken on the left and just barely touching on the right.
    demet

  11. #11
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    It wasn't broken on the left when I removed it, but I'll make sure the replacement is correctly installed. Thank you for highlighting that.

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