One of the most important things to know about a trailer is if its tires have enough air in them. If you don't want to stop your vehicle periodically so you can crawl around under the trailer with a tire gauge, a remote tire pressure monitoring system is invaluable. At the very least, it can protect the investment you have in your trailer's tires (and it may even prevent an accident). A number of these systems are available. One that's been around for a while is the Tire Sentry, which can monitor tire pressure on both the tow vehicle and a trailer. Similarly, the high-end PressurePro Wireless Tire Monitoring System lets you position multiple monitors on the wheels of a trailer and provides continuous information on the tire pressure while you drive. The monitor itself can be mounted on the dashboard of the tow vehicle and will display the tire pressure in psi, bar or kPa, whichever the driver prefers. A telescoping antenna lets the monitor in the tow vehicle stay in touch with the monitors on the tires. It can even log up to 45 days of pressure information in its memory circuits.
The Tattle-Trail TTK towing monitor system can monitor vibrations in any towed vehicle and alert the driver if they become excessive. These vibrations could result from problems with the tires, the suspension or even a loose hitch. In an extreme case, the monitor could tell the driver that the trailer has become completely disconnected from the tow vehicle, a situation that clearly qualifies as an emergency.
Possibly the most intelligent towing monitor is the aptly named Yazaki Intellitow Monitor announced in 2007 by Yazaki North America. According to a press release from Yazaki, it provides real-time diagnostics about a trailer's running lights, right and left turn and brake lights, and backup lights, as well as the status of the trailer battery's charge circuits. The Yazaki monitors are even submersible, so they can be used when towing a boat. The availability of this product isn't yet known, but it sounds as though it would nicely complement the monitors listed above.
Go to the next page for more information on towing monitoring systems.