How to Replace a Dodge Ram Backup Light Switchby Kyle McBride
The backup light switch mounts on the side of the manual transmission on your 2008 Dodge Ram 1500. If you have an automatic transmission, the transmission range sensor handles the function of the backup lights in lieu of a switch. There is no adjustment for the backup light switch and no way to repair it. If it's bad, replace it. Check the ground first, however, since a bad ground can give the same symptoms as a failed switch.
Park your Ram 1500 on level ground. Find the electrical ground for the backup light switch circuit. The ground is connector No. G107 in the engine compartment, high on the passenger-side fender, just forward of the firewall. Make sure the ground bolt is tight and there's no corrosion between the contact surfaces.
Chock the rear wheels. Position the floor jack under the frame rail just forward of the transmission crossmember bracket. Lift the truck -- one side at a time -- and support it on jack stands.
Find the backup light switch connector high up on the passenger side of the transmission, just behind the transmission case seam. The connector is on the wiring harness that also branches out to the oxygen sensors. Disconnect the connector and remove the mounting bolt for the switch. Remove the switch.
Install the new switch and tighten the bolt to 88 inch-pounds. Plug in the connector. Lower the truck to the ground.
- To test the switch, disconnect the negative battery cable and then use a multi-meter to check for continuity between the two pins of the backup light switch connector. There should be continuity when the gearshift is in "Reverse," and no continuity when the gearshift is in any position other than "Reverse." If either of these conditions fail, the switch is bad.