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Convert 24V Wiper Motor to 12V.

Discussion in '70-Series Tech' started by Skrewball, Feb 17, 2017.

  1. Skrewball

    Skrewball TLCA#18502 SILVER Star

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    Couldn't find a 12V wiper motor for a 70 series very easily, so i looked at alternatives.

    I noticed that the motor portion on an FJ60 looked identical to what i had on the BJ75.

    DSCN0110.JPG

    Since I'm no electric motor specialist, i did some internet searching to see what the main difference between a 12V & 24V motor is. What i found was that the winding size and amount are really the biggest, if not only, difference.

    When pulling the two apart, i couldn't tell much difference between the two. The only noticeable differences were some subtle wiring differences on attaching to the board that housed the brushes.

    Once i put the two armatures next to each other, i could see the winding differences.

    DSCN0114.JPG

    12V is on the left and 24V is on the right. The 12V has thicker wire and fewer wraps. The 24V has thinner wire and more wraps.
    *they are not clamped in the vise, just setting in it.

    The 12V armature fit into the 24V housing just fine, everything dimensionally was the same.

    The outer motor can had to stay the same 24V one because of a tiny mounting bump and a drain hole due to overall mounting orientation.

    The hardest part of the whole switch over was holding the brushes so the armature could be removed and installed. I just cut a small piece of plastic packaging and slid it in between the brushes and the armature. When removing the outer motor can, hold the output of the assembly and keep it from turning. That will keep the armature in the housing and keep the brushes intact.

    I haven't tested this fully on the truck, but all the bench testing seems like it will work just fine. I'll update this to be sure it is 100% functional when i get the truck back together.

    Only real practical application that i can think of is a truck that is getting a re-power and converting to 12V. Just so happens that is what the BJ75 is getting!
     
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  2. chrisspaulding

    chrisspaulding

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    I think I might have an extra 12 volt 70 series wiper motor if your conversion doesn't work out.
    Chris
     
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  3. beno

    beno Gihee Arakawa Supporting Vendor Moderator

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    Uh.... if you had a real parts guy you would know the 12v wiper motor is readily available.

    :)
     
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  4. JuanJ

    JuanJ

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    Hello,

    Put very simply, high voltage electrics allow for more efficient current use.

    This is also the reason why rotors/armatures are wired differently. The physics behind this is rather simple; however, I recommend a visit to your local electric shop for a rewire.

    While in theory 24V stuff can work using 12V, this is not always the case. If I remember correctly, the heat generated in a conductor is proportional to the square of the voltage; fire likelihood is a nasty side effect of this.

    A knowledgeable parts guy, as per @beno 's advise, is a good option.

    Hope this helps.





    Juan
     
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  5. jblueridge

    jblueridge SILVER Star

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