1. Visually Compare the Control Box
Open the body of your ride-on car to expose the original control box. Carefully remove it (power off and disconnect the battery first for safety). Place the old and new control boxes side by side. If their shape, mounting hole locations, and connector arrangements match exactly, the new unit should fit into your car’s chassis without modification.

2. Check the Connector Type
Count the pins on the main wiring harness plug—most 12 V ride-on cars use a 7-pin unilateral socket. Verify that the plug on your new control box has the same number of pins and the same socket orientation. If they look identical, the wiring harness will plug in directly.

3. Verify Model Number and Voltage
Locate the model number printed on your original control box. Typical markings include “RX23-12V” or “RX43-12V CE FC.” Confirm your replacement part bears the same model code and is rated for 12 V operation. A mismatched voltage specification can prevent your car from running or damage its electrical system.

4. Perform a Frequency‐Match Procedure
If your control box uses a wireless remote (2.4 GHz or Bluetooth), you must sync it to your car before first use or after installing fresh batteries:

• Install two AAA 1.5 V batteries into the frequency (remote) unit, observing correct polarity. Close the cover; the indicator LED will flash three times to confirm power.
• Press and hold the frequency-match button (often labeled “car select”) for about 2 seconds until the LED begins to flash continuously.
• Switch on the ride-on car’s power. When the indicator LED on the controller turns off, frequency matching is successful.
• If the LED remains flashing, turn the car’s power off and repeat the pairing steps.

5. Test All Functions
Before fully reassembling the car, temporarily reconnect the battery and turn on the power. Test forward and reverse motion, steering response, horn/beep functions, and any built-in music or lights. If everything operates smoothly, you can close up the body panels and secure all fasteners.

6. Troubleshooting Tips

• If the car powers on but won’t respond to the remote, recheck the frequency-matching procedure or replace the AAA batteries in the remote.
• If the motor doesn’t run, inspect fuse holders and wiring for loose connections or corrosion.
• Verify the ride-on car’s main battery is fully charged and able to deliver sufficient current to the control box and motors.

By following these steps—visual comparison, connector verification, model/voltage check, frequency matching, and function testing—you can confidently ensure your new control box fits and works perfectly in your ride-on car. Enjoy the ride!