Scissor Lift Goes Up but Won’t Come Down? 9 Causes & Troubleshooting Steps

If your scissor lift raises normally but will not come back down, the problem is often located in the lowering-control, electrical, hydraulic, or safety system rather than the lifting pump itself.

A machine that can raise the platform has already confirmed that at least part of the hydraulic and electrical system is operating. The next step is to determine why hydraulic oil cannot return correctly or why the control system is not allowing the lowering function.

This guide explains the most common causes of a scissor lift that will not lower, how to diagnose the problem step by step, and when replacement parts may be required.

Safety Reminder: A raised scissor lift creates serious crushing and fall hazards. Do not work underneath an elevated platform unless the machine is properly supported according to the manufacturer's service procedure. Never place any part of your body beneath an unsupported scissor stack.

Why Does My Scissor Lift Go Up but Not Come Down?

When a scissor lift raises normally but refuses to lower, the fault usually involves one of the components responsible for releasing hydraulic pressure or sending the lowering command.

Common causes include:

Emergency stop or control-selector issue
Faulty joystick or platform control box
Damaged wiring or electrical connectors
Lowering solenoid not operating
Lowering valve stuck or blocked
Emergency lowering system problem
Hydraulic contamination or restricted oil flow
Cylinder or mechanical binding
Safety sensor or control-system input

The important point is that a no-lower condition does not automatically mean the hydraulic cylinder or valve must be replaced. Electrical and control faults can create exactly the same symptom.

Infographic showing the main causes of a scissor lift that raises but will not come down

Start by Identifying What Still Works

Before replacing any component, observe the machine carefully.

Ask these questions:

Does the machine raise normally?
Does it drive normally?
Does the lowering command work from the ground controls?
Does it work from the platform controls?
Can the emergency lowering system lower the platform?
Can you hear a solenoid or valve clicking when DOWN is commanded?
Are any fault codes or warning lights present?
Did the problem appear suddenly or gradually?

These observations can quickly separate a control problem from a hydraulic problem.

9 Common Causes of a Scissor Lift That Won’t Come Down

1. Emergency Stop or Control Selector Problem

Most scissor lifts use emergency-stop switches and a control selector as part of the machine's enable circuit.

If an emergency stop is engaged or a control-selector switch is not making proper electrical contact, some machine functions may be disabled.

Check:

Platform emergency stop
Ground emergency stop
Platform / ground selector
Enable or trigger switches

Do not assume the switch is functioning simply because it appears to be in the correct position.

2. Faulty Joystick or Platform Control Box

The platform control box sends operator commands to the machine control system. A worn joystick, damaged switch, internal PCB fault, moisture damage, or loose connector may prevent the lowering command from reaching the valve system.

Possible symptoms include:

Lift works from ground controls but not platform controls
DOWN command works intermittently
Joystick must be moved repeatedly before the machine responds
Other platform functions are also unreliable

If ground controls operate normally, inspect the platform control box, joystick, connectors, and wiring before replacing hydraulic parts.

3. Damaged Wiring or Loose Electrical Connectors

The lowering circuit depends on a reliable electrical signal reaching the solenoid or control valve.

Inspect for:

Loose connectors
Corroded terminals
Broken wires
Damaged wiring harnesses
Pulled connector pins
Moisture inside plugs
Heat-damaged terminals

A poor electrical connection can prevent the lowering solenoid from energizing even when the valve and hydraulic system are mechanically sound.

4. Lowering Solenoid Failure

The lowering solenoid converts the electrical DOWN command into valve movement. If the solenoid coil fails or does not receive voltage, the valve may remain closed and trap hydraulic pressure inside the lift cylinder.

Possible symptoms include:

No valve click when DOWN is commanded
Platform raises normally but will not lower
Emergency lowering works but normal lowering does not
Intermittent lowering operation

Before replacing the solenoid, confirm the control signal and wiring according to the machine's service procedure.

5. Lowering Valve Stuck or Restricted

A lowering valve can become stuck because of contamination, internal wear, damaged seals, corrosion, or debris inside the hydraulic system.

If the valve does not open sufficiently, oil cannot return from the lift cylinder to the reservoir at the required rate.

Symptoms may include:

Platform will not lower
Platform lowers extremely slowly
Lowering begins and stops
Valve responds electrically but no movement occurs

Valve inspection should be performed using the manufacturer's service instructions because hydraulic circuits may remain pressurized even when the machine is powered off.

6. Emergency Lowering System Problem

Scissor lifts normally include an emergency or manual lowering system designed to lower the platform when normal controls are unavailable.

If the emergency lowering system also fails, the fault may be located deeper in the hydraulic valve, cylinder, hose, or mechanical system.

If emergency lowering works normally while electrical lowering does not, prioritize:

Control switches
Joystick or control box
Electrical wiring
Lowering solenoid
Control-system outputs

This comparison is one of the most useful diagnostic tests for a no-lower condition.

7. Contaminated Hydraulic Fluid or Restricted Flow

Dirty hydraulic oil can affect small valve passages and cause valves or solenoids to stick.

Inspect the hydraulic fluid for:

Dark coloration
Water contamination
Cloudy or milky appearance
Metal particles
Excessive foam

Also inspect the hydraulic filter and return circuit for restrictions.

Replacing a valve without correcting contaminated oil may cause the replacement component to fail again.

8. Hydraulic Cylinder or Mechanical Binding

A scissor lift can occasionally refuse to lower because the cylinder, scissor stack, pivot points, or mechanical structure is binding.

Possible signs include:

Platform begins lowering but stops at a certain height
Uneven or jerky movement
Unusual mechanical noise
Visible damage to the scissor mechanism
Platform movement changes depending on load

Mechanical problems should be inspected carefully before attempting repeated operation.

9. Sensor, Limit Switch, or Safety-Control Input

Modern scissor lifts use sensors and switches to monitor platform height, tilt, load, pothole protection, and machine position.

If a control module receives an incorrect input, it may prevent or modify normal machine operation.

Potential components include:

Height sensors
Limit switches
Tilt sensors
Load or pressure sensors
Position switches
Control-module inputs

Check the machine diagnostic display or fault-code system before replacing individual components.

Normal Lowering Fails but Emergency Lowering Works?

This is an especially useful diagnostic clue.

If emergency lowering successfully brings the platform down, the hydraulic cylinder and much of the return-flow path may still be functional.

The fault is more likely to involve:

DOWN command from the controls
Platform control box
Joystick or lowering switch
Electrical wiring
Lowering solenoid
Control-module output

This comparison can prevent unnecessary replacement of cylinders, pumps, or other hydraulic components.

Ground Controls Lower the Platform but Platform Controls Don’t?

If the ground control station lowers the platform normally but the platform control station does not, focus on the upper control system.

Inspect:

Platform joystick
Platform control box
Enable switch
Platform wiring harness
Connectors
Communication circuit

This condition strongly suggests that the main hydraulic lowering system is still capable of operating.

Scissor Lift Won’t Lower: Step-by-Step Troubleshooting

Step 1: Secure the Machine

Follow the manufacturer's safety and service procedures before inspecting an elevated platform.

Step 2: Check Emergency Stops and Control Selection

Verify that emergency-stop switches are released and the intended control station is active.

Step 3: Check for Fault Codes

Record any diagnostic codes before disconnecting batteries or electrical components.

Step 4: Compare Ground and Platform Controls

Determine whether the problem affects both control stations or only the platform station.

Step 5: Test the Emergency Lowering Function

If emergency lowering works, focus more closely on the electrical lowering command, wiring, and solenoid circuit.

Step 6: Listen for Solenoid Operation

When the DOWN command is activated, determine whether the lowering solenoid or valve produces an audible response.

Step 7: Inspect Wiring and Connectors

Inspect the control box, wiring harness, valve connections, solenoid terminals, and related connectors.

Step 8: Inspect Hydraulic Fluid and Valve Condition

Check for contamination, restricted flow, valve sticking, or other hydraulic issues according to the machine's service procedure.

Step 9: Inspect Cylinder and Mechanical Components

If electrical and valve systems are functioning correctly, inspect the lift cylinder, scissor stack, pivot points, and mechanical structure for binding or damage.

Symptoms and Likely Causes

Symptom	Possible Cause	First Area to Check
Raises normally but will not lower	Control, solenoid or lowering valve	DOWN command and solenoid
Emergency lowering works	Electrical lowering-control issue	Control box, wiring, solenoid
Ground controls work but platform controls do not	Platform control fault	Joystick, control box and wiring
Platform lowers very slowly	Valve restriction or contaminated fluid	Fluid, filter and valve
Lowering stops at certain height	Mechanical binding or sensor input	Scissor structure and sensors
No solenoid click	Electrical signal or solenoid fault	Voltage, wiring and solenoid coil

When Should You Replace Parts?

Replacement should only be considered after inspection or testing confirms the failed component.

Possible replacement conditions include:

Joystick or control box no longer sends a reliable lowering command
Wiring or connectors have severe corrosion or heat damage
Lowering solenoid fails confirmed electrical testing
Lowering valve remains stuck or damaged after proper inspection
Hydraulic hose or return path is internally restricted
Sensor or limit switch fails the manufacturer's diagnostic procedure
Cylinder or mechanical component has confirmed internal or structural damage

Do not replace a hydraulic pump simply because the lift will not come down. The pump is primarily involved in raising the platform, while lowering generally depends on controlled hydraulic pressure release.

How to Identify the Correct Replacement Part

Lowering valves, solenoids, control boxes, joysticks, sensors, and other components can look similar while using different electrical or hydraulic specifications.

Before ordering, prepare:

Machine manufacturer
Machine model
Serial number
OEM part number
Photos of the existing component
Connector photos
Valve or hydraulic-port photos where applicable
Electrical specification
Description of the fault

Do not confirm compatibility by appearance alone.

Related Scissor Lift Troubleshooting Guides

Frequently Asked Questions

Why will my scissor lift go up but not come down?

The most common causes include a faulty lowering control, damaged wiring, failed solenoid, stuck lowering valve, hydraulic contamination, sensor input, or mechanical binding.

Can a bad control box stop a scissor lift from lowering?

Yes. If the control box or joystick fails to send the correct DOWN command, the lowering solenoid or valve may never receive the signal needed to release hydraulic pressure.

Can a bad solenoid cause the platform to stay raised?

Yes. A failed lowering solenoid can prevent the lowering valve from opening even if the rest of the hydraulic system is functioning correctly.

Why does emergency lowering work but normal lowering doesn’t?

This usually points toward an electrical control problem, such as the control box, joystick, wiring, solenoid circuit, or control-module output.

Should I replace the hydraulic pump if the lift won’t come down?

Usually not. A platform that raises normally has already demonstrated that the pump can create lifting pressure. Focus first on the lowering-control, solenoid, valve, return-flow, and safety systems.

Why does my scissor lift lower slowly?

Slow lowering may be caused by a restricted lowering valve, contaminated hydraulic fluid, blocked return flow, mechanical binding, or another hydraulic restriction.

How do I identify the correct lowering valve or solenoid?

Provide the machine manufacturer, model, serial number, OEM part number, product photos, connector or port photos, and electrical specifications to the supplier before ordering.

Need Help Finding the Correct Scissor Lift Replacement Parts?

If troubleshooting confirms a failed control box, joystick, lowering solenoid, hydraulic valve, sensor, wiring component, or other part, compatibility should be verified before ordering.

SAIYIS supplies aftermarket replacement parts for scissor lift maintenance and repair, including control boxes, joysticks, hydraulic components, valves, electrical components, sensors, switches, and other AWP replacement parts.

For compatibility verification, provide:

Machine manufacturer
Machine model
Serial number
OEM part number if available
Photos of the existing component
A brief description of the problem

Contact SAIYIS for replacement-part identification and compatibility assistance.