If you want to send me a email on what it looks like. Pictures of the machine and display. [email address removed]. Could read what it's doing.

Thank you for the reply
I think you scared me enough to not get involved in it,
I was hoping I could get it to run for like 10-15 minutes at a time to move stuff in a shop I am putting together,
Thanks again
I will put it back on marketplace where I got it, hopefully get my $450 back

How good is the battery? 24v or 36v? Need a good battery for it to operate normal. 25+ volts or 37 volts. Of below by 3 volts on total voltage, it's a battery issue. You have brushes in all the motors to operate. Check brushes. If those are not worn into the holders, then it's a drive fuse and or contactor. Fuses need to be removed to test. Some have come apart due to poor soldering. Since you have hydraulic function. Is it slow?
If fuses are good. The contactor for drive functions 4 ways. One side is off while the other pulls in for travel, but off send power the opposite way. The tips cannot be burnt up. Unplug battery to check. They can be pushed in manually to check for binding or other issues. Use a mirror to check tip condition. This unit is old school components. Many other parts can fail to stop travel. Handle travel switches can go bad. There should be an error displayed on display. 24, 23, are known travel codes. There are diodes, recs, cards etc that can fail to cause this as well. Again check display while trying to travel.
There's also a switch for floor to step on and also a brake switch on the drive motor. All complete the circuit to drive. Floor, brake, handle switch in that order. The floor switch is in the lower right corner and fun to get at. This should also turn on the pump for the power steering. The brake switch also is an issue and maybe caused by no brake fluid. That's under a cover above drive motor. DOT 5 only. Beyond that can be a big mystery for wiring.

For these older units to travel it needs to go past 3 switches. Presence pedal -> brake pedal -> brake switch -> multi function handle -> SCR panel. If you are unable to move, somewhere in this chain one of the switches is not closing, typically it is the brake switch near the drive motor as the brake isnt fully releasing.

The hydraulic controls are also very finicky, valves and solinoids love to get stuck so you most likely have an issue with your tilt solenoid or valve.

Help this helps, let me know if you have any additional questions or want more clarification on the travel issue.