M Body Brake switch removal.

Interior and Electrical

  1. Rustyroger

    Rustyroger Well-Known Member

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    Hello again guys.
    The brake lights on my 1984 Fifth Avenue don't work, I checked the bulbs, all good, so I turned to the switch. The plunger seems to be sticking, I got it moving but not enough to make contact, no surprise there.
    How do I remove the switch?, can it be overhauled?. I cant go to the nearest auto parts store and get one and want to use the car this month.
    Thanks in advance,

    Roger
     
  2. Aspen500

    Aspen500 Well-Known Member

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    The switch bracket is held to the column with a bolt unless later cars used something different that I'm not aware of, which is very possible.

    Do the brake lights work if you connect the two wires together? If yes, it is the switch. No way to overhaul them. Try spraying WD-40 or something similar into the switch and work it back and forth a bunch of times. If it is sticking, that may get it freed up again. I've never run into a sticking switch before but anything is possible.

    If the lights don't work with the 2 wires hooked together, it may be a broken wire at the turn signal switch. The brake lights run through that switch if the brake and turn use the same bulb(s). More than once, I've seen the wire broken right at the switch. Every time the signals are used, the wire bends and over time, it can fatigue and break off.
     
  3. Rustyroger

    Rustyroger Well-Known Member

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    The brake switch is entirely disconnected from the turn signals. UK law requires amber turn signals front and rear operating independently from all other lamps.
    I'll put up a picture of how I got round this later.
    It seems my model has a different switch because it has cruise control, however I shall use a door lamp switch through a relay if necessary.
    Many thanks for your quick reply btw. :)

    Roger
     
  4. volare 77

    volare 77 Well-Known Member

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  5. Rustyroger

    Rustyroger Well-Known Member

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    No, it looks like a relay either behind or part of the switch. But thanks anyway.
    Now it's confession time; "Always check the obvious", well someone my age who made a living fixing cars for many years would do that, obviously. :oops: So why didn't I look at the fuse? :oops:
    I replaced the blown fuse, and now I have working brake lights again. :D:D:D

    Roger.