Draw-Tite Trailer Light Control Module

Dim, flickering, or erratic trailer lights are one of the most common headaches in towing, and they often trace back to a tow vehicle whose tail light circuits simply cannot carry the extra load. Draw-Tite's trailer light control module offering centers on the ModuLite power module line, designed to solve this problem by powering trailer lighting directly from the tow vehicle's battery rather than through the vehicle's own signal wiring.

How Draw-Tite ModuLite Power Modules Work

A ModuLite module reads the low-current turn, stop, and tail signals from the tow vehicle and uses them as triggers. The module then supplies the trailer's lights directly from the battery. According to the manufacturer, this approach keeps the tow vehicle's tail, turn, and stop lights from being exposed to any additional loads. The design is also intended to remove the need for a heavy-duty flasher, since the trailer lighting power comes straight from the battery.

Draw-Tite's module designs are built to avoid sending feedback through the vehicle circuits, and the trailer brake lights override the hazard lamps when the brakes are activated. That means trailer brake lights stay illuminated even when the tow vehicle's hazard flashers are in use.

Features Worth Noting

• LED and incandescent compatibility: Current ModuLite HD models work with either LED or incandescent bulbs on both the vehicle and the trailer.
• Built-in protection: Integrated re-settable short circuit and overload protection safeguards the module and the tow vehicle from wiring mishaps during installation.
• Multiplex-friendly: HD Protector versions work with most vehicles that have a multiplex lighting system, though they are not suited to vehicles with a low-side switch.
• Flexible wiring: Units can be used on a 2-wire or 3-wire system, and some versions come with a wiring harness.
• Rugged construction: The HD Protector is built with all solid-state components in potted encapsulation and an integrated protective cover.

Choosing the Right ModuLite

The ModuLite family spans several tiers, from the HD Protector to the HD Plus and Ultra Protector variants. The key spec to match is amperage. The HD Protector is rated for up to 4.2 amps on the turn/stop circuits and 7.5 amps on the taillight circuit, while the Ultra Protector with integrated circuit and overload protection is rated for up to 4.2 amps on turn/stop circuits and 16 amps on the taillight circuit. Add up the load of every light on each trailer function, including marker and clearance lights, before choosing a module. Trailers with multiple tail lights, long light bars, or LED conversions on one side of the vehicle benefit most from the added headroom.

The Ultra Protector is also described as a universal design for most vehicles, including hard-to-wire models, with circuitry that handles pulse width modulation systems. Some European vehicles often fall into that category.

Installation Considerations

Because the module draws from the battery, installation involves running a power lead from the battery to the module location near the rear of the vehicle, and fusing it appropriately. This is straightforward for most DIY installers who are comfortable with basic 12-volt wiring. Pair the module with a quality connector or custom harness for a clean, reliable hookup.

Part of a Broader Towing System

Draw-Tite is a name that has provided trailer towing systems since 1946, and its electrical products are designed to complement its custom-fit hitches. Learn more about the manufacturer on the Draw-Tite brand page, or compare options from other makers on the Trailer Light Control Module category page.