512 BBi window switch repair | FerrariChat

512 BBi window switch repair

Discussion in 'Boxers/TR/M' started by pshoejberg, Jul 30, 2021.

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  1. pshoejberg

    pshoejberg Formula 3
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    Dec 22, 2007
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    Peter H
    My left hand side window has been a bit intermittent on upstroke since I got the car and the right hand side window suddenly stopped working in fully open position a few days ago. I could hear the window motor working in down stroke direction but the motor was completely silent on up stroke indicating lack of power supply. I immediate suspected the notorious window switch problem with burnt contacts due to the relatively high current draw through the window motor. It is possible to get new aftermarket switches but the original style switches are NLA parts. Based on that I decided to attempt to repair my two original switches and it turned out to be easier than expected. After 2 x 30 minutes I had 2 well functioning original switches installed again and both windows fully operational. Below is a small summary for those who wants to try to save their switches or at least extent their live span. I know the ideal solution is to install power relays close to each door powered directly from the fuse board and hack into the motor wires in the door connector, but I'm struggling to find room for the relays without having to dismantle half of the car so until further I live with the original setup. My window motors are freshly greased and window channels and steel wires are all new and well adjusted resulting in little friction in the system. Anyway this is the procedure:

    Pry out the switch using fingers or a soft plastic pry bar:

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    Pry off the aluminum facia with care. You only need to work it slight on one side:

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    Pull out the toggle. Take care not to loose the small white extension piece:

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    Cut the melted securing pins. One pin on each side:

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    Gently open the contact housing. Take care not to drop any pieces. Take a photo or note position of the parts for later re-assembly:
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    Observed severe burning on most of the points so I polished all contact points. It is much easier to take out all parts to ensure a good even and straight polish quality. I started out with size 600 paper and ended with size 1200 using electrical cleaner / lubricant to wet the paper:

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    Re-assemble the contact. Ensure all parts are lined up correctly. Lube the switch with electrical contact spray only. I cut a profile in two of the lower plastic fins in order to install a crimp plastic sleeve to keep the contact together (I cut the top of two securing pins of to dismantle the housing):

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    Push down the toggle and re-install the aluminum facia:



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    I checked the switches with my Ohm meter before installation. Zero resistance. I measured more than 1 ohm in the defect contact before the repair.

    Best, Peter
     
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  2. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
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    romano schwabel
    #2 turbo-joe, Jul 30, 2021
    Last edited: Jul 30, 2021
    great writing peter
    but 1 ohm before repair is nothing, could it be you mean 1 K-ohm? only 1 ohm is nearly nothing. but may be when there came power on the resistance increases?
     
  3. pshoejberg

    pshoejberg Formula 3
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    #3 pshoejberg, Jul 31, 2021
    Last edited: Jul 31, 2021
    Thanks Romano. 1 ohm doesn't hear like much but a contact set should be zero as were the other contacts. When current is drawn the resistance eventually increases so much that no effect are carried across the points.

    Best, Peter
     
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  4. mexicruiser

    mexicruiser Karting

    Aug 28, 2012
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    Jon
    Glad you could recover these original switches, to avoid damage I did install the relays in the door, it was easier than I thought. No hacking as I used compatible connectors, just routed a 12gauge power from an available terminal on the fuse block.
     

    Attached Files:

  5. pshoejberg

    pshoejberg Formula 3
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    Dec 22, 2007
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    Peter H
    Great solution Jon. I might choose to go that route later if I for some reasons need to dismantle my door plates in the near by future. There are plenty of space in the doors. Only concern I have is routing the high gauge power wire (And ideally also a ground wire) through the door gab. I wish I had prepared the door harness for this modification when I restored the car.

    Best, Peter
     
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