well if you're just wanting to see if the motor will run you can jump across the main (large) poles on the solenoid and the motor should run. If it does then you are looking at checking the signal that triggers the solenoid. Start at the lift switch and follow the wiring down the handle , through the harness and to the solenoid.
make sure the lift switch has continuity when pressed. Check the signal voltage at the solenoid when pressing the lift switch.
A fairly simple troubleshooting routine to do.

if the motor does not run when jumping the solenoid then the motor has an issue like bad brushes or something.