Hi all,


I was going through the 2 underhood auxillary relay boxes on my 2003 F-250 5.4L cleaning the terminals and applying silicone dielectric grease to protect them from this winter's salt. One box has the 2 square relays for the ESOF, and the other box has 2 small rectangular relays for the directional signals and 1 larger square relay. That's the one I cannot ID. According to my EVTM manual, the relays feeding the trailer connector parking lights, backup lights, and the circuit for charging a trailer battery are in the CJB, otherwise known as the underdash fuse panel. Does anyone know what that third relay is for in the box with the 2 directional signal relays ???


RON

 

I can Email you the page i found in the shop manuel. PM me your email address.