Electronic Control Units (ECU) and Towing Looms

Why do I need an Electronic Control Unit (ECU) on my towbar?

It would be true to say that, as an Electrician, I can wire almost anything from high voltage to 12 volts in a car or caravan.

Then, along came the computer in motor vehicles. Computers are energy management systems. They monitor and control most of the energy associated with a motor vehicle, including the 12v system.

Your car’s electrical system has been designed to examine all circuitry every millisecond and raise alarms when the car’s computer identifies any system that is out of specification.

These alarms include low volts, high volts, cable temperature, etc. as they examine even the humble light bulb.

When an installer adds cable to a plug at the tow bar, he adds resistance called OHMS. The car computer only recognises factory-installed settings; therefore, it issues a fault and renders that circuit inoperable.

There are two fixes available.

• You can install an ECU (image to the right). This controller also has an image above.
• A more expensive but convenient option is to purchase a plug-and-play look kit.

This simple ECU has 5 pole or circuits and the main power circuit. It draws power from the battery and powers lights through relays in the ECU.

Therefore the car computer does not know it is connected as there is no extra circuitry or resistance that the vehicle computer can detect.

The plug-and-play loom kits are more expensive but simpler to install. Below is a photo of a simple plug-and-play loom.

Important

Do yourself a favour and install a cable larger than your battery requires.

If, by chance, you need more power around the tow bar area, then you need not upgrade your power feeds.

Please remember to size your earth return the same size or larger than your main power cable.

News Articles on Towing Equipment

• ECU Towbar Wiring Harness Loom Connector
• New Caravans and Weighbridge Certificates
• Guide to Wheel Bearings
• Overview of ADR 62/02 (Mechanical Connections Between Vehicles)

Links to Associated Administration Pages below

• Our Care, Your Warranty
• 60-Day Return Policy
• Shipping Policy
• Terms & Conditions
• Wholesale Application
• Submit A Review
• Overview of ADR 62/02 (Mechanical Connections Between Vehicles)

© Steve Wotherspoon 17th May 2018