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Recent content by BrownBear

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    JLG wiring diagrams: meaning of solid black triangles

    I acquired a JLG 40H that previous owner seems to have done significant rewiring on, and have started puzzling through the schematics to try and make sense of it all. Possibly a dumb question, but what do the black triangles signify? The blurry text doesn't help with the interpretation, but my...
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    Ford LRG423 Choke

    I can't verify this on my own machine right now, but electric choke heaters are generally supposed to be energized 100% of the time the ignition is on. A few seconds of heating during starter operation isn't long enough to affect the choke position. My guess is you have the wrong wire going to...
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    Ford LRG423 Choke

    Also make sure you are getting 12V to whatever wire hooks up to the choke. On my JLG 40H, anytime the ignition system is energized, the choke is getting power. If you're not seeing that, time to dig out the wiring diagram.
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    Ford LRG423 - Zenith Model 33 carb rebuild advice

    1997 JLG 40H with Ford LRG423 dual fuel. A lot of difficulty starting, spark ok, so suspecting a carburetion issue, I picked up a rebuild kit for the Zenith Model 33 carb. It turns out I don't understand the idle circuit on this carb. There is an idle port and screw at the base and two plugs...
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    Ford LRG423 Choke

    Put an ohmmeter across the terminals. You should measure 10-15 ohms. If there's no continuity then one or more of the leads to the delicate heating coils inside is probably broken. I had this problem on my own LRG423 and was able to stretch out the coil to form a new lead. If the resistance is...
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    JLG 40H no proportional controls

    Baby's first lift, a JLG 40H 1997 with Ford engine and 3 PQ Controls at the platform. s/n 047753030030541 All the ground controls and platform switch controls work as expected but none of the proportional controls does anything. PO says they worked intermittently and in certain positions before...
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    JLG 40H w Ford & Zenith carb: choke electric characteristics?

    At ambient temp 65F, if I apply 12V to the terminal, the choke gradually goes from fully closed to fully open in about 1 minute. Seems qualitatively right anyway according to my reading on electric+bimetal chokes, so I'm going to call this a successful repair.
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    JLG 40H w Ford & Zenith carb: choke electric characteristics?

    Got a Zenith 15080, Ford part # F8JL-TA, with an electric choke. Removing the carb for cleaning, the choke terminal thumbscrew was seized and trying to force it loose I felt something snap inside the choke. Opening it I found fragments of a plastic stop for the terminal bolt head and two very...
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    JLG 40H 1997 platform controls troubleshooting: PWM or not?

    Thanks @MarshallPowerGen for pointing me at the technical supplements. I'm not sure exactly which controllers I have but looks like most of them do emit PWM so guess I'm going shopping for an oscilloscope
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    JLG 40H 1997 platform controls troubleshooting: PWM or not?

    Hi, I just bought a 1997 JLG 40H that operates normally from ground controls, but the engine dies when switched to platform controls. It has spent a lot of time sitting outdoors in extreme weather so I am bracing myself for finding a variety of issues in the controls and boom wiring. The machine...
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