Troubleshooting Trailer Wiring Where Bulb Keeps Blowing Out

Updated 05/04/2026 | Published 05/02/2026

Products Featured in This Question

Peterson Light Kit for Trailers Under 80" Wide - 20' Harness - Driver and Passenger

(83)

$43.90

Replacement Light Bulb # 1157

(79)

$2.59

Question:

Hi, in the last year or 2 I rewired my trailer with a Peterson Light Kit for Trailers Under 80 Wide - 20 Harness - Driver and Passenger kit. It was working great, until recently I noticed one of the bulbs was burnt out. I just changed it this week, and now noticed the new bulb is burnt out. Im not sure where to start. Could the light fixture be bad? Could it be something else? How would I test? Thanks for any help!

asked by: Brad M

Expert Reply:

Hey Brad, what is most likely going on is that there's a short on the wiring for the circuit that has the bulb that keeps blowing out. Go over that circuits wire looking for any cut/exposed wire and fix as needed. Most likely it's exposed wire touching the trailer frame. If it's not there it is something to do with the trailer wiring connectors either on the tow vehicle or the trailer. Look for issues there and fix as needed and let me know what you find.

The bulb replacement would be a 1157 like the # A1157B.

expert reply by: Jameson C