The Open Road

Busta 4 Make Adaptor

Busta 4.2 Installation and Usage Guide

Introduction: The Busta 4.2 is designed for compatibility with all 12-volt negative earth towing vehicles that adhere to European lighting regulations. This guide will help you install and use the Busta 4.2 to provide your vehicle with trailer recognition and control the trailer’s lighting circuits.

Important Safety Note:

  1. The Busta 4.2 can become very hot during operation. Ensure proper ventilation and avoid placing it on or near heat-sensitive materials.

Installation Steps:

  1. Carefully read this entire guide before beginning the installation process.
  2. If you are unsure about any step, seek assistance from someone experienced.
  3. Refer to the ‘You Will Need’ list near the end of this guide and gather all the required tools and materials before proceeding.

Cable Information:

  • The Busta 4.2 comes with a 600mm (2ft) 7-core cable, with each wire rated at 10 amps.
  • It does not include trailer connectors due to global variations. Obtain locally the connectors needed to convert the Busta 4.2 into an in-line adaptor.
  • Local connectors may have different terminal uses and wire color codes. When in doubt, follow the suggestions provided for connector terminal usage. This will aid in troubleshooting any issues later on.
  • Refer to the plug and socket wiring page at the end of this guide to document the wire uses and colors on your trailer.

Wiring Information:

  • The Busta 4.2 uses the Australian trailer wiring color scheme: Yellow (left turn), green (right turn), red (brake light), brown (park and license plate light), and white (earth).
  • Each LED driver circuit can handle up to 4 amps of LED current.
  • Do not connect traditional lamps (light bulbs) to the LED driver circuits on the trailer.
  • The blue and black wires pass through from end to end and can be used for any purpose.
  • If you don’t need these wires, you can cut them back and leave them disconnected.

Connection Instructions:

  • The Busta 4.2 is labeled “VEHICLE” on one end and “TRAILER” on the other.
  • Attach the plug that fits into your vehicle’s socket to the cable from the “VEHICLE” end.
  • Attach the socket that fits your trailer’s plug to the cable from the “TRAILER” end.

Final Steps:

  • Follow the fitting instructions provided for your chosen connectors and attach them to the Busta 4.2 cable ends.
  • At the connection points, remove the minimum amount of outer sheath necessary to make all the wiring connections.

By following these instructions, you can safely and effectively install the Busta 4.2 for improved trailer recognition and lighting control with your towing vehicle.

Testing and Sealing Trailer LED Connections

Testing Trailer LEDs

Step 1: Preparation

  • Ensure the vehicle’s ignition and lights are switched off.
  • Connect the trailer to the vehicle.

Step 2: Initial Check

  • Turn the ignition on.
  • Check if any trailer LEDs that were blinking have stopped.
  • Verify if the trailer’s telltale (indicator) operates correctly with turn and hazard signals.

Step 3: Brake Light Test

  • Start the engine.
  • Turn on the park lights.
  • Operate the foot brake to confirm the operation of the brake LEDs.
  • Ensure there are no lamp failure warnings.

Step 4: Troubleshooting

  • If you encounter lamp failure warnings, refer to the troubleshooting guide on the last page of the manual.

Sealing Cable Ends After Testing

Step 1: Cable End Sealing

  • Busta 4.2 cables are internally sealed during manufacture.
  • As an extra precaution, seal the ends of the 7-core cable inside the connectors.
  • Apply a small amount of silicone sealant or liquid electrical tape to the open end of the outer sheath.
  • Use a small screwdriver or similar tool to push the sealant into crevices if necessary.

Step 2: Inspection

  • Before fitting the connector covers, inspect the sealing at the cable ends.
  • Ensure they are properly sealed.
  • If re-sealing is needed, add more sealant.

Operational Note

  • Always connect and disconnect the trailer with the vehicle’s ignition and lights switched off.
  • Connecting or disconnecting the trailer with the vehicle’s ignition and/or lights switched on may cause malfunctions or unintended operation by some vehicle computer systems.

Tools and Materials Required

  • Busta 4.2
  • A plug to fit your vehicle’s trailer socket
  • A socket to fit your trailer plug
  • Silicone sealant or liquid electrical tape
  • Hand tools: side cutters, wire strippers, screwdrivers, needle-nosed pliers

These revised instructions provide a step-by-step approach with clear headings and simplified language for better understanding.

Warning – High Operating Temperature

The Busta 4.2 can become very hot during operation.

Important Note on Towing: If your vehicle does not have an electric brake controller, it should not be used to tow a trailer with electric brakes without a wiring modification. When you turn on the park lights, one of the circuits in your vehicle will activate the trailer brakes. When you turn off the park lights, the trailer’s brake solenoids release energy, which can potentially damage the Busta 4.2 and your vehicle’s lighting controller.

Modification Instructions: To prevent potential damage, open the trailer plug and disconnect the trailer’s electric brake wire (usually Blue for Australia) before towing. Reconnect the wire when you’ve finished towing.

Caution with Load Resistors: Do not connect the Busta 4.2 to a trailer with load resistors, as they and LED arrays may draw more current (up to 4 amps) than the Busta 4.2 can handle. Remove any load resistors from the trailer before connecting the Busta 4.2.

Horse Float Lighting: Some horse float manufacturers may connect non-LED lights inside their trailers to the park light circuit of the trailer. Check the type of lights and which circuit they are connected to before connecting the Busta 4.2. If these lights draw too much power for the Busta 4.2 (max 4 amps), you may need to replace them with LED lights or modify the trailer and vehicle wiring for a different power source.

Trailer Brake LEDs Pulsing: New high-end electric brake controllers emit pulses to the trailer’s electric brake solenoids for connectivity and warnings. Some trailer manufacturers install a diode that causes the trailer’s brake LEDs to flash with these pulses. The Busta 4.2 cannot stop this pulsing. To test, with the ignition on, temporarily disconnect the trailer’s electric brake wire (blue in Australia) at the plug. If the brake LEDs stop blinking, contact the trailer manufacturer to locate and remove the diode from the trailer wiring harness.

Warranty Information: The Busta 4.2 Mk4 comes with a two-year warranty against defects in parts and manufacture from the purchase date. While it’s sealed to the IP-68 rating, it’s not covered against internal or external corrosion or any damage due to liquid or dust ingress once in operation. We recommend regular checks for possible entry points (nicks, cuts, abrasions, etc.) and sealing them with silicone sealant to prevent damage. For repairs, please return the Busta 4.2 to LAB Electronics, as it contains no user-serviceable parts.

Compatibility and Regulations: The Busta 4.2 Mk4 is designed for 12-volt DC negative earth vehicles and trailers. Each LED driver circuit can handle a maximum of 5 amps of current. Do not connect any lamps (light bulbs) to the LED driver circuits on the trailer. Note that the Busta 4.2 does not conform to E/ECE/324 – E/ECE/TRANS/505 regulations. It has only one park light circuit and does not monitor the trailer’s turn signal LEDs. Therefore, it’s the driver’s responsibility to ensure all vehicle and trailer lighting functions correctly.

Trailer Lamp Failure Warning and Troubleshooting Guide

Introduction: If you’ve encountered a trailer lamp failure warning in your vehicle when using the park and stop lights, this guide will help you understand the issue and provide step-by-step instructions on how to resolve it.

Why You May Receive a Trailer Lamp Failure Warning: In most vehicles, the lamp check modules do not have the capability to check a trailer’s park and stop LED circuits. To account for this, load resistors are typically installed inside devices like Busta 4.2 and Euro units. However, these resistors generate heat and consume power unnecessarily when not needed. As a result, they are often left unconnected.

What to Do If You Receive a Trailer Lamp Failure Warning: If you receive a trailer lamp failure warning, follow these steps carefully. If you’re unsure or uncomfortable performing these tasks, seek assistance from someone experienced.

Step 1: Disconnect the Cable Gland Tail:

  • Locate the cable gland tail on the trailer end of the unit.
  • Using a thin spanner, grip the 19mm (3/4in) body nut of the cable gland to prevent it from rotating on the end plate.
  • Loosen the tail with another 19mm (3/4in) spanner.
  • Once loosened, unscrew the tail completely by hand and slide it along the cable away from the body.

Step 2: Prepare the Unit for Inspection:

  • Remove the black silicone sealant from the two screw holes in the trailer end plate using a hobby knife or similar tool.
  • Remove the two screws from the end plate and ensure that the O-ring seals under the screw heads are still intact.
  • To access the rubber seal, carefully move the end plate a short distance along the cable, then move it back against the case of the unit.
  • Grasp the seal and slide it along the cable as far as you can away from the body. Check that the sealing gasket on the end plate is not damaged.

Step 3: Identify and Work with the Wires:

  • Retrieve the three insulated wires with pre-stripped ends from inside the unit.
  • Note that the White wire has an end cap fitted, while the Red and Black wires have plastic sleeves over the bare wires at their ends.

Understanding Wire Functions:

  • White wire: Earth wire.
  • Black wire: For the park circuit load resistor(s) – one resistor for the Mk4 and two resistors for the Euro.
  • Red wire: For the stop circuit load resistors – two resistors in all units.


  • If you have a lamp failure warning only on the trailer park circuit, connect the Black wire to the White wire.
  • If you have a lamp failure warning only on the trailer stop circuit, connect the Red wire to the White wire.
  • If you have a lamp failure warning on both the trailer’s park circuit and the stop circuit, connect all three wires together.

Step 4: Terminate the Wires:

  • Unscrew the end cap from the White wire and remove the sleeve from the Red and/or Black wires.
  • Straighten the bared wire ends and twist the ends of the required wires together.
  • Screw the end cap from the White wire over the twisted wires to terminate the required two or three wires you have connected.
  • If only two wires have been terminated, leave the sleeve over the remaining unused wire. If all three wires have been terminated, the plastic sleeves are no longer needed, so dispose of them thoughtfully.

Step 5: Reassemble the Unit:

  • Apply a small amount of neutral cure silicone sealant around the surface of the end plate gasket.
  • Reattach the end plate using the original screws (ensure that the O-rings under the screw heads are still in place).
  • Apply a small amount of black neutral cure silicone sealant to cover the screw heads as they were originally sealed.
  • Slide the rubber seal back into the cable gland.
  • Hand-tighten the tail onto the cable gland using two 19mm (3/4in) spanners, with one being thin to prevent breaking the silicone sealant seal between the cable gland nut and end plate.

By following these steps, you can effectively address a trailer lamp failure warning and ensure proper functionality of your trailer’s park and stop lights.