Welcome to ZRoadster.org - BMW Z1 Z4 Z8 Z3 Forum and Technical Database

If you want to join in with the discussion, and see the areas which are available only to members then sign up now!

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Microswitch Replacement - How To

Discussion in 'Z3 Roadster & Coupé' started by g8jka, Apr 28, 2012.

  1. g8jka

    g8jka Zorg Guru (III)
    British Zeds

    Joined:
    Dec 5, 2011
    Messages:
    1,867
    Likes Received:
    1,164
    Trophy Points:
    148
    Location:
    Telford, Shropshire
    Model of Z:
    Z3 - 2000 2.8 Roadster
    After having intermittent problems with the electric roof on my zed and identifying the problem to be a faulty microswitch, I decided I would finally cure the problem and replace the switch. It is a fairly simple job but does require a little modification from the old switch to the new switch.

    Here is how I did it:

    Firstly you need to purchase a new microswitch to replace the old one. I got a miniature microswitch with lever from Maplins for the cost of £2.49.

    [​IMG]

    Next step is to remove the casing that houses the current microswitch situated in the middle of the roof just above the passenger window. To do this it is easier to lift the roof a little so that the housing is in full view. To remove the screws a T25 torx tool needs to be used.

    This is what we need to remove

    [​IMG]

    All removed

    [​IMG]

    Rear view showing the switch itself that needs to come out

    [​IMG]

    Now remove the wires leading to the switch and pop out the actual switch itself and put the casing somewhere safe

    [​IMG]

    Cut off the two wires leaving you with just the microswitch. Below shows the old switch removed and the new switch that needs to be fitted

    [​IMG]

    As we can see there is a difference between the two switches, the main one being the lever which is longer and has a U shaped bend at the end of it. This is where we need to modify the switches as the lever on the new switch is not long enough to reach outside of the casing and to touch against the roof when it closes, deactivating the switch and circuit

    [​IMG]

    I cut the lever off the old switch and glued it into place onto the new microswitch lever, leaving me with a new switch and a lever long enough to press against the hood and working the microswitch as it should

    [​IMG]

    Only two of the terminals are needed to make the microswitch work so I removed the middle one to allow a little better access for the wires when they are put back into the housing

    [​IMG]

    Now back to the car where we need to extend the wires that will connect to the switch. As the terminals are separate on the new switch the wires are not long enough to reach both of them. The plastic now needs to be pulls back to give a bit more access to the wires so they can be extended a little. I added a little bit of wire onto each of the wires coming upto the switch by soldering them and finishing with heat shrink so that it is nice and neat and finally added two small spade terminals to the end of each extended wire. I also put some heatshrink over the end of the plastic after pulling it back to protect the wires

    [​IMG]

    The switch can now be put back into the housing with the wires connected and can now be tested to make sure it works.The roof should go up and down with the lever in its normal position and should not go up and down if the lever is depressed so that the switch clicks and closes the circuit (as if the roof was closed)

    [​IMG]

    Hopefully if all is working correctly the housing can be put back and secured with the torx bolts removed earlier

    [​IMG]

    Carefully close the roof keeping you eye on the lever making sure it contacts the roof, pressing it down so that it clicks the microswitch and shuts off the circuit so that the roof will not open with the roof closed. Then open up the roof as per usual lifting it into position so that the lever no longer contacts the roof, creating the switch circuit and allowing the roof to be opened as normal with the roof switch and brake pedal. Some adjustments may need to be made to the lever to make sure it contacts the roof, if it is to short it won't contact the roof and press the switch meaning the circuit is always made and the roof motor will work all the time even with the roof locked into position if the button and brake pedal are used as usual. If it is too long it may just snap off the lever of the new microswitch, again making the circuit all the time meaning the roof will work in all positions if the button and pedal are pressed.

    If all goes to plan, you should now have a working microswitch and a fully functioning roof :)
     
  2. Aceman

    Aceman Moderator
    British Zeds 3rd Party Trader

    Joined:
    Dec 5, 2011
    Messages:
    2,204
    Likes Received:
    707
    Trophy Points:
    156
    Location:
    Wakefield
    Model of Z:
    ///M Roadster
    Excellent writeup and almost identical to how I did mine a few years ago on the 2.8 using exactly the same microswitch. Here is a picture of how I did mine;

    [​IMG]

    I am sure Gary will be along shortly to put this in the Wiki :-bd
     
  3. Snoops

    Snoops Zorg Addict

    Joined:
    Dec 10, 2011
    Messages:
    338
    Likes Received:
    4
    Trophy Points:
    51
    Location:
    Red Rose Country
    Model of Z:
    2.8
    Nice detailed and clear write-up :-bd
     
  4. GazHyde

    GazHyde The Gaz Monkey
    Staff Member Administrator Global Moderator British Zeds

    Joined:
    Dec 2, 2011
    Messages:
    15,104
    Likes Received:
    9,159
    Trophy Points:
    226
    Location:
    Newbury, Berkshire
    Model of Z:
    BMW Z4 3.0Si Sport
    Excellent stuff! :-bd

    Added to the list of Wiki's to be created and copied to the knowledge base!
     
  5. g8jka

    g8jka Zorg Guru (III)
    British Zeds

    Joined:
    Dec 5, 2011
    Messages:
    1,867
    Likes Received:
    1,164
    Trophy Points:
    148
    Location:
    Telford, Shropshire
    Model of Z:
    Z3 - 2000 2.8 Roadster
    I did see your post on how you did yours I tried to take the lever out of the old switch and mount it like yours but in the end thought it would be easier just to glue it to the new lever as I was unsure on how to pack it out.
     
  6. Aceman

    Aceman Moderator
    British Zeds 3rd Party Trader

    Joined:
    Dec 5, 2011
    Messages:
    2,204
    Likes Received:
    707
    Trophy Points:
    156
    Location:
    Wakefield
    Model of Z:
    ///M Roadster
    I seem to recollect it was a small piece of hardwood I used to pack it out but it doesn't matter which way you do it the end result is the same. Thanks for the writeup it is one of those jobs that many have done but nobody has properly documented so I am sure there will be alot of appreciative people reading it in the future. :-bd
     

Share This Page