How to Test a Convertible Top Motor: A Step-by-Step Guide

If you own a convertible car, you know how important it is to have a working convertible top motor. It is the motor that operates the convertible top, allowing you to open and close it. If your convertible top motor is not working correctly, you may experience difficulty in operating your car’s convertible top, which can ruin the fun of driving with the top down.

In this article, we will provide you with a comprehensive guide on how to test a convertible top motor.

Understanding the Convertible Top Motor

Before we dive into the testing process, it is essential to understand the convertible top motor’s role and how it operates. The convertible top motor is typically located in the trunk of your car and is connected to the convertible top via a series of wires and hydraulic lines. When you operate the convertible top switch, the motor receives a signal to engage and operates the hydraulic system to lift or lower the top.

Symptoms of a Faulty Convertible Top Motor

Before we begin the testing process, it’s essential to understand the signs of a faulty convertible top motor. Some of the most common symptoms of a faulty convertible top motor include:

  • The convertible top won’t open or close.
  • The convertible top opens or closes slowly.
  • No sound or movement when attempting to open or close the top
  • The convertible top moves unevenly.
  • Strange noises coming from the motor.

Tools Needed

Before you start testing your convertible top motor, make sure you have the following tools:

  • A digital multimeter
  • A hydraulic pump and fluid
  • A voltmeter
  • Electrical tape
  • A fuse puller
  • A test light
  • A wiring diagram for your vehicle
  • Basic hand tools (screwdrivers, pliers, etc.)

Safety Precautions

Safety is paramount when working on your car. Here are some safety precautions you should take before testing your convertible top motor:

  • Disconnect the battery to prevent electrical shock.
  • Make sure the car is parked on a flat surface and the parking brake is engaged.
  • Keep loose clothing and long hair away from moving parts.
  • Use safety glasses to protect your eyes from debris.

Step-by-Step Guide on How to Test a Convertible Top Motor

Testing a convertible top motor involves a series of steps that can help you identify any issues that may be causing it to malfunction. Here’s what you need to do:

Step 1: Inspect the Motor and Electrical Connections

The first step in testing your convertible top motor is to inspect it for any signs of damage or wear. Check the wiring and electrical connections for any signs of corrosion or fraying. Make sure the motor housing is free of debris and that the motor itself is securely mounted to the car’s frame.

Step 2: Check the Fuse and Relays

The next step is to check the fuse and relays that control the convertible top motor. Refer to your car’s owner’s manual to locate the fuse box and the convertible top relay. Use a multimeter to test the fuse and relays for continuity, and replace any that are blown or faulty.

Step 3: Test the Voltage

Once you’ve checked the fuse and relays, it’s time to test the voltage to the motor. Use a multimeter to test the voltage at the motor’s electrical connection. You should see a voltage reading that corresponds to the specifications in your car’s owner’s manual. If the voltage is too low, it could be a sign of a faulty switch or wiring issue.

Step 4: Test the Motor

With the voltage confirmed, it’s time to test the motor itself. Connect the motor directly to a power source, such as a car battery, and listen for any sounds of operation. If the motor does not operate, it could be a sign of a faulty motor, a wiring issue, or a problem with the hydraulic system.

Step 5: Test the Hydraulic System

The final step in testing a convertible top motor is to test the hydraulic system that operates the top. Check the hydraulic fluid level and make sure it’s topped off. Listen for any sounds of operation when activating the switch, and inspect the hydraulic lines and cylinders for any signs of leaks or damage.

Common Problems with Convertible Top Motors

Even with proper maintenance and testing, convertible top motors can still experience issues. Here are some of the most common problems:

  • Faulty switches: The switch that activates the motor can wear out or fail over time, preventing the top from functioning.
  • Electrical issues: Corroded or frayed wiring can cause voltage drops and prevent the motor from receiving the power it needs to operate.
  • Failed relays: If the relay that controls the motor fails, it will prevent the motor from receiving power.
  • Hydraulic issues: Low fluid levels, leaks, and faulty cylinders can prevent the hydraulic system from operating properly.

Troubleshooting Common Convertible Top Motor Problems

Here are some common convertible top motor troubleshooting tips to help you identify and resolve the issue:

Broken Fuses

If your convertible top motor isn’t working, it could be due to a blown fuse. Check your car’s manual to locate the fuse box and determine which fuse is associated with the convertible top system. If you find a blown fuse, replace it with a new one and test the motor again.

Damaged Wiring

Over time, the wiring that connects the convertible top motor to the rest of the system can become damaged or disconnected. Inspect the wiring carefully for any signs of fraying or corrosion. If you find any issues, repair or replace the wiring as needed.

Faulty Switches

The switch that controls the convertible top motor can become worn out or damaged over time, causing the motor to malfunction. To test the switch, disconnect it from the wiring harness and use a multimeter to check for continuity when you press the switch. If there’s no continuity, the switch may need to be replaced.

Hydraulic Fluid Leaks

If your convertible top system is hydraulic, there could be a leak in the hydraulic lines or cylinders that is preventing the top from functioning correctly. Look for signs of fluid leaks around the convertible top system, and check the fluid levels regularly. If you find a leak, have it repaired as soon as possible.

Malfunctioning Sensors

Some convertible top systems use sensors to ensure that the top is fully closed or open. If these sensors malfunction, they can prevent the motor from working correctly. Check your car’s manual for information on how to test these sensors and replace them if needed.


Q: How often should I test my convertible top motor?

A: There’s no set timeline for testing your convertible top motor. However, if you notice any issues with your convertible top, it’s best to test the motor immediately.

Q: How long do convertible top motors last?

A: Convertible top motors can last up to 10 years, but it depends on how frequently you use them and how well you maintain them.

Q: Can I test my convertible top motor myself?

A: Yes, you can test your convertible top motor yourself using a voltmeter and an ohmmeter.

Q: Can I test the motor without a multimeter?

A: No, a multimeter is necessary to test the motor properly.

Q: Can I test the limit switches without removing the motor?

A: Yes, you can test the limit switches without removing the motor by using a multimeter.

Q: How can I prevent issues with my convertible top motor?

A: Perform regular maintenance checks and tests on your car’s convertible top motor and ensure that it’s properly lubricated and free from any debris.


Testing a convertible top motor may seem like a daunting task, but with the right tools and knowledge, it can be done easily. By following the steps outlined above, you can determine the cause of any issues with your car’s convertible top motor and take the necessary steps to fix them. Remember to always work carefully and refer to your car’s manual for specific instructions.

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