I got my JLG 40E running great, but it now is stuck in slow motion mode again. Checked all limit switches, replaced with New batteries $$$$$.. , replaced Sevcon board, replaced speed dial on platform, had right drive motor rebuilt $$$, and all boom functions move very slowly. My drive functions do not move at all. But this strange operation happens. For example if I'm in the boom and doesn't matter which operation I engage, as long as I press the steering button and a operation button it will immediately go into the faster mode like normal operation. To recap as an example, pressing the upper boom and the steering button it will move great. Or if I press the lower booms and the steering button the lower booms work great? Any thoughts?
really need some help trying to fix this? Could this be a issue with the change over contactor? I'm getting good voltages based on other threads in this forum that have had similar problems.
We have a pair of JLG 600's that are electric and they behaved similar to that when the pump was on its way out. Functions were painfully slow but some would speed up if you toggled another function. If system pressure is low and the pump gets scorching hot, the pump is bypassing.
My drive forward and reverse are not working but all boom functions work, just very slow. Had both drive motors rebuilt and connected properly. I'm leaning towards the change over contactor not fully operating but they either work or don't work is my understanding. When the drive is engaged, the unit will click, click,click at the contactors and no movement in forward or reverse. When I press the steer and any other boom operation, it works fine??
That's a strange one for sure. I'm not very familiar with your particular model but I would suspect your slow boom functions are more the result of hydraulics rather than electrical. The drive issue has me a bit puzzled though. Do you have access to a JLG Analyzer?
If I'm not mistaken the 40E has electric drive motors. If that's the case, with you having problem with both drive not functioning properly and boom functions not functioning properly, the two are not directly related. The steer function Tee's off the same pump output line as the line that feeds the boom functions control valve. If you can toggle steering and make boom functions work somewhat better, disconnect the hose that feeds the steering valve and plug that hose, now see if your boom functions improve.
That would make sense. I once had a 450AJ lose all toggle switch functions but if I ran the steering over relief, I would get the functions back. Chunk of an o-ring had jammed a two way check valve inside the hydraulic manifold.
Thanks for the help guys, I will attempt to plug the steering hose and see if that improves this weekend. Fingers crossed.
unfortunately I do not have access to a analyzer.
The JLG analyzer does not work on the 40e with the sevcon. There is a "calibrator" that was used on them that had limited capability compared to the current unit introduced with the e series scissor lifts. If you changed the sevcon the new one might have some options set up incorrectly.
That is good to know. I've never came across a JLG that wouldn't work with the analyzer so I thought it worked with all JLG equipment. Thanks for the info.
anyone want 10,000 lbs of scrap metal?
Check your voltage at pin 4 orange wire on the sevcon, should be 48v from the elevation switches when in the stowed position. Also check pin 7 yellow wire, should be 48v when the unit is level. Pin 13 white/violet is the signal from the pump speed control and pin 14 white/black is the drive accel signal. Your issue is consistent with loss of level signal from the tilt sensor. I believe there is connector in the drive tray connecting the JLG harness to the Sevcon one and they would often lay in the bottom of the tray in a puddle of water and the pins would turn green.
Hello, the sevcon has different colored wires. The color of the wires do match on the connector connected to the side of the JLG rectangular motor controller and I get 46 Volt at pin 4 with foot on platform pedal and no function pressed 0 volt at 7 with foot on platform pedal and no function pressed 0 volt at 13 with foot on platform pedal and no function pressed 4.1 volt at 14 with foot on platform pedal and no function pressed Thanks!
OK, so your elevation switches are working but no signal from the tilt sensor. The tilt sensor has three wires, a hot and ground going in, and one with 48v out when the sensor is level. The wire colors at the sensor could be different but according to the print pin 1 on the connector white/yellow>green should be 48v+, pin 2 blue/red>white is 48v out when level, and white/brown>black is ground. The output from the tilt sensor also goes upstairs to the tilt relay to shut off the tilt alarm and light. Let's start with telling the sevcon the unit is level and go from there. BTW the manual is up on JLG's site on the public side.
Ok will test tomorrow rick, the mosquitoes are verocious out right now.... I have the schematic manual but the quality of the diagrams are difficult to read. How may I find them on the public side? Ok I found the manuals..Thanks
They are difficult to read. If you print them out sometimes you can fold an edge back and match it up to the corresponding page.
Unit is level with the bubble in the middle of the tilt sensor. We open the connector from the tilt sensor and measured 48 volts on pin 1 white/yellow. no voltage on pin 2 blue /red. Should we be reading the voltage with the connector connected to the tilt sensor at pin 1 or should pin 2 have voltage as well?
Pins 1 & 3 should power up the sensor (hot and ground) and 2 should have 48v coming out of the sensor when level. Check for voltage between 1 & 3, should be 48V. Is the led on the bottom of the sensor lit up? You could try to jump power to the blue/red wire to simulate a signal from the tilt sensor that it is level.
I have the light lit up green on the bottom of the censor. The PIN number 1 + 3 does have power going in but I did not get power coming out. Power going in was 47 volts. I jumped Pin 1 and 2 as shown in the picture and ground connected.It is still moving in slow motion
Do you now have 48v at pin 7 yellow on the sevcon? If so check pin 13 white/violet with a boom function engaged and vary the boom speed knob. That will tell us if the sevcon is seeing the boom speed command.
Yes, I am getting 47V at pin 7 yellow. When I engage a boom function at pin 13 with the speed control knob at the detent I get 2 volts. As I turn it clockwise (speed up control knob) the voltage drops from 2 volts slowly down to 0 volts when the speed knob is all the way fast. If I stop the speed knob half way between slow and fast it will remain at around 1 volt give or take.
We're making progress. If the unit was working correctly the boom functions would go into creep mode when above elevation and tilted. Does the pump speed knob have any affect on the boom speed? I'm not sure what the speed signal should be at pin 13 other than it comes from pin 2, up through the pot, then back down to pin 13. With the pot fully clockwise the reading should be the same at 2 and 13. I had a cheat sheet from when the 30E first came out but that's long gone. What is the voltage across the battery pack?
Across the battery pack we are getting 47.5 volts Yes the pump speed knob works but it is still in a lethargic mode. When turned to the slowest setting the booms barely move if at all. When the speed knob is turned to the fast setting the booms lift but very slowly as if it were in a creep mode but as soon as you press the steering function either left or right, the booms kick into normal high speed operation. With the platform foot switch pressed and no other functions activated, we get 2 volts at pin 13. When you turn the speed knob this volts progressively lowers down to zero. It progressively increases back to 2 volts when turned the opposite way. I will have to try pin 2 tomorrow am as a massive thunderstorm is approching. We truly appreciate the effort to fix this and we will compensate you once its running. Thanks again
Can you plug it in? 47.5 volts is nearly dead. Fully charged resting voltage should be 50.4 and will approach 60 as the charger is finishing up.
Haven't charged in a week but will place it on charge. Replaced 4 batteries and prior to the replacement was getting 38-41 volts. It actually was working fine even back then. I've lifted the steering wheels to get a full turn left to right or right to left and the unit still will 'kick" into normal operation at the 47.5 volt when the steering wheels turned and a boom function in operation. Will charge over the weekend and retest the above procedures again.
When you activate steer a contactor puts full power to the pump motor bypassing the sevcon. When operating normally the sevcon meters the current going to the motor. Some of these had low voltage protection built into them. You may want to check the individual batteries and charge some individually or in pairs if they are out of balance, also check the pack voltage under load.
Charged over the last few days. Problem still acts the same. Battery 1. 6.56 v 2. 6.31 3. 6.78 4 . 6.27 5. 6.96 6. 6.81 7. 6.70 8. 6.54 Will attempt the procedures above again.
Rick, Fully charged and tried all above procedures. Still no go. Any idea how to get the drive motors to function? Looks like the booms will not speed up and may take to repair facility. Just cant figure this out...... Can we try and tackle the drive motors. Moving the joystick I get nothing. Neither forward or reverse... So frustrated!!!
could the proportional relief valve cause the lift to operate in slow motion mode? When activating the steer function it "kicks" into normal operation. Thinking outloud to get this thing fixed to cut hurricane trees down on the property.
I purchased a 1996 JLG 40E a few months ago. All functions seemed to work fine, all lift functions, rotation, etc. but the drive system was very slow and lethargic no matter how the potentiometer was set. When I checked the batteries that the previous owner had in place, they were a hodgepodge of different sizes with only 3 of the correct batteries, so I purchased a complete set of new, correct batteries. The drive was still lethargic and now the lower boom tries to lift but does not rise more than an inch no matter what the potentiometer is set at. Frustrated I left it alone for a week, when I went back to it now the lower boom works fine for a while, then while I was trying to use the unit, now the lower boom won't lift anymore and has not since. Yes, the drive is still lethargic and I actually had to tow the unit with my tractor at one point to get it to move. I tested the motor controller and the voltage from the #4 pin and B- is over 50 volts, both static and under drive. I jacked up the drive wheels and they both move in both forward and reverse, but had no real power. Are these two issues, failure of the lower boom to lift and lethargic drive connected? All other functions work fine. Can anyone help me figure this one out. Thanks in advance!
hey Art, I still have the same issues with mine. I have all new batteries, drive motors were rebuilt and still is slow motion. I may replace the motor controller but thats $$$$ and I can't figure anything else as I've checked all wiring and fuses and such.
Really frustrating
I keep reading about how the speed potentiometer gets forced beyond the normal stop, causing creep mode to stick, but cant find how to really fix or bypass it. The lower boom has worked sporadically, but now tries to lift, but wont.
that would make sense. Since we have the same issue I'm sure we can try a couple of things. I'm heading out of town for a week but will try and troubleshoot again. My steer functions work fine as thats on a separate circuit. My drive and boom functions are very slow... If I press a steer on the joystick and try to elevate a boom, it "kicks" into normal operational mode. Does yours do that?
Upper Boom lift, extend, tilt, rotate all work as they should. The lower boom lift tries, pump starts, boom moves a tiny bit, but the pump continues with no more action. When you reverse the lower boom to move down it jumps down the tiny bit it moved. I have not tried flipping the steering rocker while trying to elevate the lower boom, but I will try that tomorrow. Have you replaced the speed potentiometer and if so did it make any difference?
Yes I replace the speed pot, and replace the joystick as well as mine unit will not drive either. Also the tilt sensor was replaced and both limit switches on the booms seem to check out fine. My booms will lift about a couple of inches and then you can hear the pump still running but it doesn't budge. My speed pot would go past the indent and I thought that was the issue, but the new one didn't fix my problems. I'll keep trying after my trip.
Sounds like we have identical problems, except I have not replaced anything but the batteries at this point. How did you test the limit switches and where are they? I thought about replacing the joystick, but when I jacked up the drive wheels, the joystick worked fine, but didn't seem to have much power and that seems crazy as electric motors have a great deal of torque normally. My unit is a 1996 and from what I could find, they didn't come with the "Creep Mode", but it certainly acts likes that is what it is stuck in. I'm going to check out the motor controller and see if I can tell if that has been changed out, and if so the replacement might be newer with the "Creep Mode". One thing that is driving me crazy is the fact that the lower boom worked fine with the crappy batteries that were in the unit when I purchased it, but now, with new batteries it has worked sporadically, but now just tries to lift. I kept trying it and the lower hydraulic cylinder blew a seal, so I had it rebuilt, no leak now, but still won't lift. I actually wonder if the cylinder was bad before, but all of the lift pressure went to that cylinder and over pressured it, but I don't know. There is only one hydraulic pump, that switches from one function to another. The upper lift works great, the boom extension works fine, drive works on level ground with minimal power, but will not climb any grade at all and the lower boom will not work now. I don't understand!!
search this in this forum.. its my previous troubleshooting
JLG 40E boom synchronizing
98 JLG 40e Problem
oh and I did replace the sevcon but have not replaced the motor controller. This may be my next purchase as I thought the Sevcon was the issue.
Art, Can you try this to see if you have the same issue on your lift. From the platform, press the steering either left or right, doesn't matter which. The while holding the left or right steering press the boom function that was running slowly. Does your unit "kick" into fast mode by moving the boom faster? This is exactly what my lift is doing. Thanks
I am new to this board and need some wisdom. I have read through previous posts on similar problems but have a new problem. I am Resurrecting a 1996 JLG 40E that has been sitting for a while.... re-packing hydraulic seals one-by-one. Batteries are charged and boom, turn table and steering function correctly. Since its last move 4-5 months, it has recently developed drive issue with the electric motors. From the platform, Lift moves both forward and reverse , only a few feet then Plug brakes apply and all functions cease (like a controller trip). I set it up on blocks with the drive wheels elevated (no load) same results. The only way to move again is resetting foot switch. No flash codes are visible on the JLG (Sevcon). I think it was replaced by previous owner. Part ID in the manual identifies controller as 7013310-40e. But label on the back of the JLG MOS90d DC controller Part # 7013311(with a Date code on the Sevcon is 10/22/01). Any suggestions?
I'm still trying to get my 1996 JLG 40e problems figured out. I am still having drive issues, low power with all brand new batteries. It moves, but any incline at all it seems to stall, as if it is stuck in "Creep Mode". From what I understand that up thru 1996, the controller did NOT have creep mode built into them. From what I can find, the controller for the 1996 40e manlift was a part# 1600175. The controller that is installed in my unit appears to be the aftermarket unit 7011942/E120-1226. I have a suspicion that this may be the problem. If this controller is from a newer unit that has CREEP, could it be the cause of the slow, low power issue? When I test the voltage it is over 50 volts, so that isn't an issue. I will be happy to provide a phone # for anyone who is knowledgable and would be willing to help me deal with this. Thanks!
willie69 has experience with JLG. maybe he will chime in with some insight on both our units
I don't think those units used a creep mode on the drive motors, the drive joystick control simply sends input to the MOS90 motor controller for fwd/rev direction and proportional speed input. The MOS90 does everything from there. Have you checked the LED on the MOS90 to see if it's flashing any fault codes? Aside from that, if you suspect a problem with the MOS90, call Hindley Electronics and see if they can test the unit, or if they can't if they can recommend someone who can test it. It's been years since I've worked on one of those, but I do recall sending one off once to have it tested, just can't recall who I sent it to. Be sure and check all your contactors, look for evidence of one with burnt contacts or even one stuck.
thanks for the recommendation, will call the start of the week
It’s alive!!!!! After replacing all the least expensive items I have been running around chasing one problem after the next. I finally bought a new controller and everything works.