CURT 58240 Tail Light Converter — Non-Powered 3-to-2 Wire Splice-In for Incandescent Lights

The CURT 58240 is a non-powered splice-in converter that adapts a vehicle's 3-wire taillight circuit to a 2-wire trailer setup for reliable incandescent-taillight towing.

When a vehicle lacks a dedicated trailer outlet, the CURT 58240 provides a straightforward, long-lasting method to create one by splicing into the existing taillight wiring. Instead of relying on plug-in adapters or vehicle-specific harnesses, this converter is meant to be mounted inside the vehicle and hard-wired into the taillight circuits. It is designed specifically for systems with incandescent (non-LED) lights and supplies separate signal and taillight outputs for proper trailer illumination.

How does this converter create a trailer connection?

The CURT 58240 taps into the vehicle's taillight wiring and combines signals to produce the standard 2-wire trailer feed. Installation requires connecting color-coded wires to your vehicle's circuits and mounting the unit inside the cabin or trunk area for protection from the elements.

• Splice-in design for direct connection to taillight wiring
• Converts a 3-wire vehicle circuit to a 2-wire trailer output
• Color-coded leads simplify matching signal and taillight wires
• Blunt-cut wires arrive ready for soldering or crimping

Is this unit compatible with LED lighting systems?

No — the 58240 is not suitable for vehicles or trailers with LED lights. Because it is non-powered and relies on incandescent signal characteristics, using it with LED circuits can cause improper operation or insufficient current for LED indicators.

• Intended only for incandescent taillight systems
• Do not install on vehicles with factory or aftermarket LED lights
• LED setups typically require powered or electronic converters instead

What should I expect during installation?

Installation involves locating the vehicle's taillight wiring, splicing the converter leads to the corresponding wires, and securing the module inside the vehicle. No heavy-duty flashers or battery taps are necessary; the unit manages signal and taillight circuits at automotive-safe amperages.

• Mount interiorly (trunk or cargo area recommended) to protect from moisture
• Color-coded wires: signal circuit rated ~2.1 amps, taillight circuit ~5.0 amps
• Requires standard electrical splice tools: crimp connectors, solder, heat shrink, or butt connectors
• Works with a 4-way flat socket if you choose to add one for easy trailer hookup

Will this converter handle heavy trailer loads or auxiliary circuits?

The 58240 is designed for basic lighting functions—tail, stop/turn, and running lights—at modest current levels. It is not intended as a high-current power distribution device and should not replace dedicated power feeds for trailer brakes, charging, or accessory circuits.

• Not recommended for powering trailer brake magnets or charging systems
• Use only for lighting signals within specified amp ratings
• For higher-demand needs, select a powered converter or vehicle-specific harness

Who is this for: The CURT 58240 suits vehicle owners who need a simple, durable way to provide trailer lighting when a factory trailer connector or custom harness isn’t available, and whose vehicle uses incandescent taillights. It’s an economical choice for occasional towing, DIY installers comfortable with basic splicing, and those adding a 4-way flat plug without needing heavy-duty power outputs. If your vehicle has LED lights or you require high-current trailer functions, consider a powered converter or a vehicle-specific wiring harness instead.