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JLG 60H no function from dump valve #2

Discussion in 'Forklifts/Telehandlers' started by koalamotorsport, Feb 24, 2020.

  1. koalamotorsport

    koalamotorsport Active Member

    Aug 8, 2012
    Cleveland OH
    Hi Guys.
    This antique was working fine when I parked it before winter.

    I have no basket level/rotate, no boom in/out and no steering. All four functions are controlled via dump valve #2 and all are controlled purely from the basket with the exception of boom in/out, which can also be controlled from the ground.

    The boom in/out does not work from the ground or basket. Swing, boom up/down and drive all work from ground or basket. They are all functions via dump valve #1.

    When selecting any of the functions, the motor bogs slightly, as though it has load, but the functions do not work.

    I had previously hand an intermittent problem with these functions which I tracked to a loose ground at the dump valve itself. This is not the case now. When that happened, there was no noticeable load on the engine, unlike now.

    I have all the wiring diagrams and cannot find anything wrong in control circuits, although deciphering the relays is virtually impossible as they don't show relay diagrams, only connection points.

    When the selector switch is set to ground, both dump valve solenoids 1 and 2 are energized. Selecting to basket de-energizes both. I'm working alone and can't 100% confirm that they are being energized when operating basket controls, but by using a "record" function on my multimeter, it seems to be that they are.

    My primary question here is does anyone know if the dump valves need to be energized, or de-energized, in order for the function to work. In other words, do the dump valves power open or power closed, and are the functions operational when they are open or closed?