Union speedometer

Discussion in 'General Tech' started by skyhighZJ, Jan 16, 2020.

  1. skyhighZJ

    skyhighZJ Thanks for your taxes

    Joined:
    May 31, 2012
    Location:
    Aberdeen, NC.
    Got the S10 I bought from @Lizooki on the road last night and drove to work this morning. It runs like a champ and it feels good to be rowing the gears again! I noticed this morning on the way to work that on right hand turns and the straight away that follows the speedo works. Turn left and it dies until you turn back to the right. Doesn’t have to be a sharp corner just a RH curve will do the trick. Am I looking at a possible loose electrical connection on the trans? Or, is it a union employee and only working when it wants to? Btw: 1991 s10 2wd 5 speed.
     
    Last edited: Jan 16, 2020
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  2. frankenyoter

    frankenyoter No Rain, No Rainbow

    Joined:
    Mar 17, 2009
    Location:
    DARK CITY
    Blinker fluid relay is shorting out on the canooter bypass valve on the trans.

    or a loose connection or a possibly a bare wire/ground.
     
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  3. a_kelley

    a_kelley mechanical fixer

    Joined:
    Jan 26, 2010
    Location:
    Rutherfordton
    There is a "digital ratio adapter" that connects the sensor to the cluster. Look for generally loose wiring, if you put the rear on stands, you can let it run in gear to read speed, and wiggle stuff with an assistant to watch the gauge. Good luck with it.
     
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  4. skyhighZJ

    skyhighZJ Thanks for your taxes

    Joined:
    May 31, 2012
    Location:
    Aberdeen, NC.
    Speedometer has basically quit working all together with a very small amount of attempting to work at very random and not re-creatable scenarios. So I have traced all wiring up to the fire wall and see no issues. Pulled the VSS and cleaned the magnet end and checked the connections. All seems good to go. I have been reading across different interwebs places (makes me appreciate this place even more looking at other forums!) a lot of people point to checking the DRAC. Only thing is I don’t know where to look and the webs places doesn’t show specifics for my truck. It is a 1991 S10 2.8 V6, 5spd 2wd (also well known as a panty dropper) does anyone have a diagram that would help me pinpoint the location? I know what I’m looking for, small white plastic box in close relation to the ECM, just don’t know where to look and not in the mood to tear the whole dash out to find it (unless I have to o_O). Thanks!


    P.S. not trying to just throw parts at it like a new vss until I have determined that’s the cause.
     
  5. a_kelley

    a_kelley mechanical fixer

    Joined:
    Jan 26, 2010
    Location:
    Rutherfordton
    I'll look at the service manual when I go to the shop tomorrow. I bet you can ohm test the sender.
     
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  6. a_kelley

    a_kelley mechanical fixer

    Joined:
    Jan 26, 2010
    Location:
    Rutherfordton
    DRAC is "under right side of dash, next to ecm."

    To test the vss, it says to disconnect the vss, use a meter set to AC volts and run the wheels faster than 3mph. (Jack stand rear, put in gear is what I would do). Reading should be between .1v and .5v AC.

    speedometer.jpg
     
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