Trailer Lights: Frequently Asked Questions

The short answer is ‘yes’. Every drawbar-type or tag-along trailer attaches to the vehicle by means of a trailer hitch or couple. Additionally, there has to be a security chain that attaches the trailer to the frame of the towing vehicle. Alternatively, the law allows using a cable of sufficient strength that is installed in the manner that allows controlling the trailer if the main coupling fails.

The short answer is both ‘yes’ and ‘no’, as it depends on the state. The majority of states does not allow more than one trailer behind a vehicle, though there are some, which allow so-called ‘triple towing’. Though, there are certain exceptions. Different states may have different law, so if you plan a trip that involves moving along several states, it’s good to check, whether all states you plan on crossing allow towing more than one trailer. The main exceptions involve towing agricultural equipment, or you are to have a DMV permission to tow more than 1 trailer with your truck.

If we are talking about the vehicle, the side marker lights (not reflectors) are required for a car, truck or SUV to be street-legal (unless it was built in 1967 or earlier). If we are talking about the trailers, the front side marker lights are required for trailers longer than 6’.

The 4-way connector is the typical trailer light connector, where yellow is for left side brake/turn signal and green is for the right side brake/turn signal, white is ground, and brown is for running lights. See the other trailer light wiring diagrams.