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So my speedometer broke...

Discussion in 'The Garage' started by 1991K5, Jul 16, 2004.

  1. 1991K5

    1991K5 Registered Member

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    So yesterday I leave for work, and once I get up to 45 mph my speedo (electric in my '91) goes haywire. Down to 5, up to 85 and everywhere inbetween the needle goes. Then today it just stopped working for the most part, except when doing 65+ on the highway where it showed I was going 9 mph before falling back to a resting position. I have no idea where to start looking on the electric speedometers, sensor in tcase, gauge itself, set it on fire /forums/images/graemlins/weld.gif ?
     
  2. Saxwonder84

    Saxwonder84 1/2 ton status

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    Just run without one. Mine hasn't worked in years. Bought a tach and decided to save my money there and waste it else where.

    Jacob

    P.S. You would think during an inspection they might check that! Oh well.
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    Put a scanner on the truck, drive it, and see if the ECM "sees" vehicle speed differently than it's displayed on the speedo.

    If the ECM sees bad info as well, it's the DRAC or the VSS itself.

    If the ECM sees what looks to be the correct speed, then its the speedo. Then again, it COULD be the output from the DRAC to the speedo I guess. Not sure how you verify that output though.

    Don't forget, this is an electrical system, it could be a bad wire or connection, so start with figuring out the general failure area, then look at connections and wires.
     
  4. surpip

    surpip 1 ton status

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    ya it sounds like a bad connection to me, i would trace the wire's from the VSS to the back of the speedo and look for worn, broken , frayed wires. Than mabey take the connections off and clean them. hope that helps,
    dale
     
  5. berg76

    berg76 1/2 ton status

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    My truck wouldnt shift into overdrive because my speedo cable broke.

    ~jason
     
  6. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    pull the VSS out and look at the reluctor ring.

    on my s10 the speedo did the same thing. a piece of metal got on the VSS and wore the notches off the reluctor ring.

    Just a thought
     
  7. 1991K5

    1991K5 Registered Member

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    Thanks for the suggestions guys, I guess I'll crawl under tommorow and see what I can find. Hopefully its a loose or bad wire.

    I would just run without it like I did for years in my '80 K5, but I'm planning on selling it... anyone in the market for a '91 K5 with a broken speedo? /forums/images/graemlins/deal.gif
     

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