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Brake warning light - what does it do

Discussion in 'Engine & Performance' started by AuroraGirl, Apr 3, 2020.

  1. AuroraGirl

    AuroraGirl Supporting Member Supporting Member

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    I DONT have a brake light on is what im saying. As in, I think it should be on because I frequently have no fluid in rear brakes, whats the reason yall thinks
     
  2. Rusty Nail

    Rusty Nail Whatever!

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    Burned out bulb?
    Lol?

    Hay did you try that?:D
     
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  3. 77 K20

    77 K20 Full Access Member

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    If I remember right the factory combo valve/proportion valve has a rubber boot on the top of it. This boot only has one wire in it. When the factory combo valve detects a problem (pressure loss) a metal piston inside moves to one side. This grounds out the pin coming out of the combo valve. If you have a meter check a few things. Pull off the wire and check the pin of the combo valve to frame ground. And/OR you can put the wire you just pulled off to ground. This should then turn on your brake light in your dash. If that doesn't do it... then burned out bulb? Your wire is broken/disconnected somewhere?
     
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  4. Rusty Nail

    Rusty Nail Whatever!

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    That stupid green wire can be the bane of existence - I swear.
    Lmao gotta love it?

    Jerry will eventually pop in and disseminate drawrings upon thee.
    All that safety stuff is on one circuit though..it gots a fuse somewhere...he always knows, and im just a schmoe.
     
    Last edited: Apr 4, 2020
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  5. 75gmck25

    75gmck25 Full Access Member

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    On my truck there is no sensor to tell you the emergency brake is on, so the dash brake light is only for the braking system.

    To test the brake Warning light I just turn the ignition to on (not to the start position) and the brake light is steady on. If it does not light up, the light bulb or circuit is bad.

    When I first got my truck the wire on the prop valve was broken, and the ground wire for the instrument panel was disconnected. Things get broken on old work trucks.

    Bruce
     
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  6. Snoots

    Snoots Supporting Member Supporting Member

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  7. AuroraGirl

    AuroraGirl Supporting Member Supporting Member

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    OH so thats the wire that my quart of ATF fell onto and pulled off that I couldnt figure out what It did. Im guessing its factory routed properly or with conduit. Mine was about 5 extra feet dangling oon the fender zip tied in a bunch. Not sure what my gpa was doing there... but Okay. And it stopped working before that, but I also blew a fuse for soemthing that i couldnt ever figure it out functioned for, so I just ignored it. Does the fuse control the choke, 4wd, seatbelt, and brake warning lamps, perhaps?
     
  8. Blue Ox

    Blue Ox Turning Diesel Fuel Into Fun

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    Well, since I think this is where the question came up, and I happen to have a squarebody in my back pocket, here is a pic of the factory switch in my '85. It's the white block at the top of the photo with the brown wire connected. The brass looking tab is what trips the microswitch. Hope this helps.

    IMG_20200404_183344071.jpg
     
    Last edited: Apr 4, 2020
  9. gotyourgoat

    gotyourgoat Full Access Member

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    Hello internet.
    ;)
     
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  10. Rusty Nail

    Rusty Nail Whatever!

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    There may be a super crappy
    Spade terminal on that steering wire that looooooves to snap off. The base is Smaller diameter than your pinky.

    And im sitting in a Honda, dont be mad...:(
    @Blue Ox with the pix makin nickels look bad.
     
  11. 80BrownK10

    80BrownK10 Full Access Member

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    I think you have pinpointed your problem;):happy175:
     
  12. 80BrownK10

    80BrownK10 Full Access Member

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    You do realize how important brakes are right?o_O:33:

    If you have puked all your brake fluid out and go to step on that petal at 50 and nothing happens....you better hope your parking brake is adjusted up and you think fast and it's strong enough.
     
  13. AuroraGirl

    AuroraGirl Supporting Member Supporting Member

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    What is a parking brake?

    Jokes aside, physically it exists but it is seized in the open position. So not working.

    And, its only the rear brakes that leak, the fronts are almost there on the hoses but not quite.good thing i dont drive onroads
     
  14. 75 short

    75 short Junior Member

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    i also have a 75 owned since new and my light does not come on when e brake is on only comes on when key is turned on
     
  15. AuroraGirl

    AuroraGirl Supporting Member Supporting Member

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    Well I think I found my issue.. must have forgot it was no longer gonna be working.

    1bc71a2428ecafbae1758c5e58ae1195.png
     

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