Troubleshooting Non-Functional Left Trailer Turn Signal in 7-Way Trailer Connector on 2008 Ford F150

Updated 03/08/2022 | Published 03/05/2022

Question:

I should mention the left blinker doesn’t work on any trailer . Would there be a short on the truck instead?

asked by: Jay

Expert Reply:

You most likely have a blown fuse. The fuse for the trailer left turn/left brake lamp circuit is in the passenger cab fuse panel in location 42.

Replace the fuse, but before plugging the trailer in, you'll want to closely examine the left turn circuit on the trailer to locate the short and repair it, otherwise you'll continue blowing fuses.

expert reply by: Mike L

Jayred S.

3/5/2022

I should mention the left blinker doesn’t work on any trailer . Would there be a short on the truck instead?

Mike L.

3/8/2022

The fact that the left turn signal doesn't work on any trailer you've tried connecting to the vehicle would confirm that the problem lies with the vehicle. I'd still lean toward a blown fuse. One of the trailers likely has a short in the left turn/brake lamp circuit which caused the fuse to blow.