rear sensor not working

Hi @deltaii ,

Here’s a link to the Parking Aid section of the repair manual for a 2004-08 F-250/350/450/550 vehicle.

A quick read through indicates that if the rear end of the vehicle is not damaged and the reversing lights work OK and if SJB (smart junction box?) fuse #35 is OK you will need a DMM and the appropriate scan tool to test out the system.

I couldn’t find the owner manual for a 2004 model to locate the SJB but in the 2008 model owner manual it shows the passenger compartment fuse box, Fuse #35 is the RSS (reverse sensing system) fuse so it may be the location of the fuse for your year model as well, just a different name perhaps. If it is blown there is always a reason why a fuse blows although sometimes a fuse can “fatigue”. This is where it just ”breaks” (operating at the high end of its’ rating over a long period of time weakens it) leaving a lot of the fuse intact rather than rupturing violently due to its’ current rating being exceeded

The sensors are powered (both voltage and earth - so no connection from the sensor to earth where they are situated) by the Parking Aid Module (PAM) when the ignition key is in the run position and reverse gear is selected

Hopefully this is a start.