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JLG 35E Won't Drive or Steer

bgares

New Member
Joined
Nov 19, 2019
Messages
1
Location
08016
Good Day All! I have a late 90's (it's either a 96 or 99, can't remember while I'm typing) JLG 35E articulating boom lift. Everything on it functioned great when purchased (bought used about 2 years ago). It needed new batteries, and some general cleanup/paint. As it was a weekend project, it took me a little longer to complete. At this point, it's been sitting for about 4 months. I finally finished cleaning everything up, painting, and installing new batteries, and battery charger. Now, all boom functions work flawlessly (both from ground, and basket). However, it won't drive or steer. When I engage the foot switch, and push/pull the joystick, I hear an audible click from the motor compartment, but no other reaction. When attempting to steer, I hear the motor running, but little to no movement of the steer wheels. The Sevcon is blinking 6 times (Faulty Drive Hand Controller). I assumed this meant the joystick was bad, so I ordered a replacement, but that provided the same results. At this point, I'm thinking it's one of the contactors in the motor compartment, but I have no idea how to diagnose them. If I'm on the right path with the contactors, how do I troubleshoot/diagnose them? If I'm not on the right path, any idea on what else I should be checking? Thanks in advance for any advice!
 

Hansen99

New Member
Joined
Jan 22, 2021
Messages
3
Location
Utah
I have the exact same issue with the exact same lift, were you able to locate the problem?
 

Txhayseed

Senior Member
Joined
Dec 23, 2019
Messages
610
Location
Texas
You should have two contactors. One is for the back up hydraulic system the other is for the main hydraulic system. The drive and steer only have one common point and that is the joy stick. Steering is done through the function manifold via coils and valve. Drive through the motor controller out the drive motors. Being that you have no steering and no drive id start to circle my wagons around a wiring issue from the joy stick/ steering rocker to the ground. You can hear the contactor closing because the foot switch is being activated and the machine is waiting for the command from what ever control function you use. You can pull the plugs at the steering coils. Have someone in the basket active steer left steer right and check for voltage to your coils. If you dont have voltage to your coils you need to back track your way to the basket. First go to your basket and open up the control box. Check for output voltage at the joy stick for steering functions. Most common area for jlgs to fail from basket to grounds is the plugs under the basket control box. You can unplug there and ohm out your control cable to the steering coils. If thats good plug it back in. Open the platform control box and do the same thing but backprobe those wires from inside. Make sure its going through the plug completely. If it is then go from the plug back inside the control box.
 

Hansen99

New Member
Joined
Jan 22, 2021
Messages
3
Location
Utah
So the JLG i have been working on i was making some great progress. I had the lift were all functions were working except the drive. all boom functions worked properly and the steer tires were working just fine, but it still wouldnt drive. This is were i left off 2 weeks ago, last week i begin working on it again, and now just over the weekend NO functions work now, nothing. I cant even get a single light to work on it. I dont know what the heck could have changed over the weekend but it will not work. All the batteries have power, and the batteries are charging properly but the machine will not function at all now. any ideas?
 

Txhayseed

Senior Member
Joined
Dec 23, 2019
Messages
610
Location
Texas
You need to run your power system. Check the main ground and main power at the batteries. Then follow it to the controller. It sounds like your loosing battery voltage somewhere along the line. Anderson plugs, terminals on power and ground to controller are common problems. Check power directly at the controller at b+ and b- to see if you have pack voltage. If you dont you have a loss in the feed via a cable. If you do you need to move to the estops and key switch for voltage.
 
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