A Truck-Lite how-to: Ten steps to a better medium-duty lighting system specification:

Gone are the days when you could significantly improve your lighting performance by simply adding LED Safety Lighting to your truck bodies. After all, LED Safety Lighting has been available since the early 1990s. Decades later, we need to add some options that will continuously improve the robustness of your system and help improve your CSA scores. A few inexpensive improvements in the design phase hold the promise of long-term savings and system reliability for the future.

Whenever we look at a medium-duty truck that a fleet uses, we need to first look at the electrical supply of the truck chassis to the truck body. Evaluate what is the nominal voltage, the circuit protection strategy, and the electrical connection system that is used to connect the wiring from the chassis to the body. The following is a checklist based on our experience that one might want to use to improve the specification of the vehicle system:

1. Get the suppliers involved (chassis, body, and lighting supplier) in the development of a fleet specification. This short meeting will go a long way to ensure a reliable, robust specification. The fleet should review the past failure mode data that was experienced for that specific class of vehicle to provide continuous improvement opportunities and look for opportunities through specification that can be improved.
2. Understand the type of nominal electrical voltage supply and the type of circuit protection system that is being planned. When we had only incandescent safety lighting we did not have to be so concerned about this because incandescent bulbs are nothing more than glowing fuses. With today’s LED electronic systems that draw only 20% of the amperage, a new fresh look at the circuit protection is necessary.
3. Pay attention to the chassis connector. A great deal of work has been done recently by the Technology and Maintenance Council (TMC) to develop a standardized TMC RP 1427 standard body-to-chassis connector which is designed to assist truck chassis manufacturers, truck body manufacturers, and equipment users with the design and manufacture of end-of-frame (EOF) chassis connectors. Strong consideration should be used during the development of a connector for this application.
4. As far as a wiring specification for your body, we recommend starting with the TMC RP 1404 Wiring Standards for the light and medium duty chassis/body interface, which is designed to help light and medium-duty truck chassis and body manufacturers standardize the truck chassis-to-body wire interface on commercial vehicles. Selecting a lighting supplier that also makes the wiring harness will help ensure continuity with the reliability of a vehicle electrical system.
5. Route the wire and connectors on the inside of the body to reduce impact of spray and physical damage. Installations following this simple specification often have wire harnesses that last the life of the vehicle.
6. Consider the proper location of the safety lighting system. This can often be a challenge considering all of the different types of equipment that can be added to your body. One of the most frequent challenges is how to properly install your lighting and reflex reflectors on vehicles equipped with lift gates. Often, the lift gates are located in an area that is also the most common lighting installation location. This can be a dilemma as there are frequent areas where the safety lighting systems can be blocked or rendered less effective. A good resource for helping determine the location for the lighting is TMC RP 1430, lamp and reflector placement for light and medium duty vehicles with lift gates.
7. Watch for physical damage risk areas. The primary reason for lighting failure on medium-duty trucks is physical damage. A small amount of time spent on selecting quality LED lights that are protected from physical damage can ensure a much longer life. Tree branches often are a primary source of physical damage; we advise that the selection of the lighting products that are fully protected by an extrusion or corner cap is an effective way to limit physical damage.
8. Protect the rear lighting which is frequently mounted on the rear posts of the vehicle. It is important to install bumpers to ensure that they are contacting the dock seal or loading dock not the lighting. Standard function of a medium-duty truck dictates that someday, the vehicle will hit the loading dock much faster than was intended. Reviewing the lighting locations and anticipating the necessary protection if this happens will ensure that the lighting will last the life of the vehicle.
9. Check the front corner caps. Some of the new plastic corner caps on van bodies may not provide adequate protection from physical damage from tree branches. If you operate your fleet in an area that has a lot of hardwood trees along the roadways, engineer your lighting package to provide improved protection. Corner caps made of casting materials often do a better job of protecting the truck body. Corrosion is failure mode number two. The second most frequent failure mode for lighting on medium trucks is corrosion. Select quality LED products that have integrated sealed connectors to provide a long life and an adequate barrier to corrosion found on today’s roads.
10. A pilot review of the vehicle with your OEM and component suppliers is often a great way to ensure that the Fleet will get the products that they specify as well as to help assure that the products have been installed properly. Many fleets as well as suppliers have helpful check lists to aid in the Pilot Review Process. Fleets, make sure you are getting the vehicle built the way you want it because you will have to deal it after you take delivery on it.

With all of the improvements that are available through new products that have been developed in the last two decades, we are nearing a time when you can “Fit and Forget” your lighting products for the life of the vehicle.