Good day all, I just found this forum and am wondering if someone could help me. I have a 1998 JLG 26MRT scissor lift that will not move. About 15 hours ago it lost low speed so I just ran it in high. Now high quit also. I'm at a loss where to start with it. There's a couple solenoids/valves on the hydraulic pump where the main feed hoses go to the driveline, but I'm unsure how to diagnose them. I found an old thread with the same problem but the only answer given was to check outriggers, which this machine does not have. Thanks for any help!!
Check control box connection and control wiring from ground to box along scissor stack and the connection. How long have you owned machine ?? Do you still have steering and lift functions ??
Yes, I still have steering and lift. I have owned for maybe 9 months and put 110 hours on it. Used it to put up a machine shop and rented it out a few times. It has 3320 hours now. The other evening I pulled the cover off the control box and when I moved the loose cover just right I could get the machine to move, so I'm leaning toward connections as you mentioned. Haven't had time to do any more diagnosing. I don't think it's the hi/low switch but anything's possible. In possibly unrelated news, it also will sometimes lose control panel enable and functions. When this happens I have to go to the keyswitch on the bottom and rotate it back and forth. Usually I gain connection again. I'm thinking the current problem may be unrelated though.
Also, I forgot to mention, at times when running the lift in high, it would actually go at low speed. Then occasionally would jump to high for a bit, and back to low, even though the switch was always in high. Maybe that means I've got two wires shorting across or something?
Sounds like you got issues with wiring for sure. I would start by checking it out