Lift Motor Troubleshooting

WARNING: Leave all work to trained and licensed electricians. Attempting repairs yourself is extremely dangerous, with the potential for serious injury and even death. Greg Smith Equipment assumes no responsibility or liability for individuals doing the work as shown.

Click on the causes for more information.





MOTOR ISSUE

CAUSE

REMEDY

The electric motor does not run.

1.) Fuse is burnt or breaker is tripped.

2.) Check for the correct voltage to the motor.

3.) Inspect all wiring connections.

4.) The “up” button is defective

5.) The AC Contactor is defective.

6.) Overhead limit switch is defective.

7.) Motor windings burned out.

1.) Replace fuse or reset circuit breaker.

2.) Supply correct voltage to the motor.

3.) Repair, replace, insulate and tighten all wires.

4.) Replace the "up" button.

5.) Replace the AC contactor.

6.) Replace the overhead limit switch.

7.) Replace the motor.

The electric motor makes a humming sound.

1.) Start capacitor is defective.

2.) The AC Contactor is defective.

1.) Replace the start capacitor.

2.) Replace the AC contactor.

The electric motor runs but will not raise the lift.

1.) Plugged oil filter screen.

2.) Cracked or loose oil suction tube.

3.) Lowering valve is stuck open.

4.) Low hydraulic oil level.

5.) Oil pump is not priming.

1.) Clean or replace oil filter screen.

2.) Replace or tighten oil suction tube.

3.) Clean or replace lowering valve.

4.) Fill tank with hydraulic oil. Refer to owner’s manual.

5.) Replace oil pump.

Electric motor runs and raises unloaded but will not raise with a load.

1.) Debris in the lowering valve.

2.) Motor operating on low voltage.

3.) Pressure adjust valve out of adjustment.

4.) Exceeding the weight limit of the lift.

1.) Clean or replace lowering valve.

2.) Supply correct voltage to the motor.

3.) Adjust or replace pressure adjust valve.

4.) Check vehicle weight and/or check for equal vehicle weight distribution.

Lift comes down slowly.

1.) External hydraulic oil leak(s).

2.) Debris in the lowering valve.

3.) Debris in the check valve.

1.) Repair external leaks.

2.) Clean or replace lowering valve.

3.) Clean or replace check valve.

Slow lifting speed or hydraulic oil seeping out of the filler/breather cap.

1.) Air mixed with hydraulic oil.

2.) Oil -return tube loose.

3.) Hydraulic system over filled.

1.) Repair external leaks.

2.) Clean or replace lowering valve.

3.) Clean or replace check valve.

Power unit is noisy.

1.) Sucking air and oil at the same time. (Foamy oil causing Cavitation)

2.) Power unit mounting bolts (to the post) are loose.

3.) Worn motor coupling. Located between the motor and pump.

4.) Plugged oil filter screen.

1.) Change old hydraulic oil with fresh hydraulic oil.

2.) Tighten power unit mounting bolts.

3.) Replace motor coupling.

4.) Clean or replace oil filter screen.

Lift stops short of a full rise.

1.) Low on hydraulic oil.

2.) Oil suction tube is too short or it has a crack in it.

1.) Add oil.

2.) Replace oil suction tube.