When it comes to trailer lighting, nothing causes more trouble than burned-out bulbs and corroded ground connections at the frame. Rubbing (and shorting) connections come in a close second. If you want to get rid of those problems forever, switch over to LED lights and add an individual ground wire to each light. The entire project takes just a few hours.
The trailer light kit we used (Blazer International No. 127680; about $54 from amazon.com) comes with a new harness. At an auto parts store, buy a spool of 16-gauge wire for the individual ground wires. Then buy crimp connectors and a few packages of split loom wiring harness protectors (Curt Manufacturing No. I-1824-25; 25-in. length; from amazon.com).
Disconnect the old trailer harness wires at each light and attach mason’s line. Then pull each line back toward the trailer tongue. Connect this “fishing line” to the new harness and loom (Photo 1). Next, pull the new harness through the frame (Photo 2). Finish off the installation with crimp connectors and heat-shrinkable tubing (Photo 3).