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Terex TB42

Discussion in 'Forklifts/Telehandlers' started by telwood, Jun 28, 2020.

  1. telwood

    telwood Well-Known Member

    Joined:
    Mar 20, 2013
    Messages:
    113
    Location:
    GA
    I own a Terex TB42 boom lift. Gas motor etc. Everything works great but last week I lost forward drive and the high speed function. I've read the other post and realize these things can be a pain.

    So I bought it from a dealer and called them to do a site service call a couple weeks ago. Called them back the other day and they pretty much whined saying their Optimizer 4 must not be working because the motor shut down every time they hooked it up. It seems like they would still be able to troubleshoot based on just not going in forward and the high speed toggle. The tech said he thinks it is wiring because the drive motors rarely go bad....who knows but I got no answers that have fixed it.

    I played with it some today just checking connections and it seems to only drive backwards no matter which direction I move the joystick. The high/low toggle does nothing as it just stays in low speed.

    Logically it seems the speed toggle must be bad and maybe the joystick? But reading about all these OEM Controls I am a bit lost what to do next. I plan to call them Monday and others and start trying to figure this out but hoped someone could enlighten me with the possible troubleshooting? All controls except those 2 work perfect.....it can't be moved from the bottom controls so I am referring to the basket controls. Wheels steer fine and all boom actions are good.

    Any opinions would be appreciated,
    Tom
     
  2. barklee

    barklee Senior Member

    Joined:
    Aug 5, 2009
    Messages:
    900
    Location:
    ohio
    Does that have the superflex circuit board in the lower control panel? We have had a few go bad and they will do some crazy and scary stuff. I would check that out.
     
  3. telwood

    telwood Well-Known Member

    Joined:
    Mar 20, 2013
    Messages:
    113
    Location:
    GA
    Yes, I am working with OEM to diagnose the Superflex board. Apparently they can be sent in for rebuild but am trying some other things first that may be the culprit
     
  4. barklee

    barklee Senior Member

    Joined:
    Aug 5, 2009
    Messages:
    900
    Location:
    ohio
    I noticed if you press your finger on the board while using the function that doesn't work it will start working if the board is bad. Try that out.
     
    mikebramel likes this.
  5. telwood

    telwood Well-Known Member

    Joined:
    Mar 20, 2013
    Messages:
    113
    Location:
    GA
    I'll give it a try...couldn't hurt.
     
  6. skata

    skata Senior Member

    Joined:
    May 10, 2007
    Messages:
    769
    Location:
    midwest
    Bad solder joint?