Nuts and Volts - July 2010

WIRELESS TRAILER

BY RON NEWTON

HTS

A friend of mine needed help solving a problem his local construction firm was having with his big gravel trailers and water tankers. His employees kept breaking the taillights and/or ripping out the towing harnesses. This caused a sizable amount of down time and expense due to repairs. As you know, it is illegal to tow without taillights, and my friend’s rigs are big. It is a disaster waiting to happen if wiring harnesses are being flexed too much.

LEDS draw small amounts of energy and can be powered using small batteries for long periods of time. That makes them ideal for this type of project.

The unit presented here can be installed in minutes and can also be carried for emergency taillights in the event the wires are ripped from the trailer.

This project does involve a small amount of surface soldering and chassis drilling. A Microchip programmer is a plus, however, programmed chips and the PCBs are available from the Nuts & Volts webstore. (I highly recommend ordering these boards directly from NV.) The board files are also on the Nuts & Volts website ( www.nutsvolts.com). You will need to cut the board (a shear works best). The cost of the parts is about $80 in addition to the boards. This may sound a little on the expensive side, but considering the cost and installation of wired taillights — especially if you have several trailers — it’s a bargain.

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July 2010

Meet the Transmitter

The transmitter is powered when you plug in the car or truck trailer connector. When the lights, brakes, or flashers are turned on, their power is used to transmit. The taillights are powered by two D batteries which should last about 100 hours with the lights on. Most trucks and cars come prewired with a trailer connector; the standard is a flat four wire connector with the designations shown below. Adapters are available for other types.