Troubleshooting Driver Side Rear Taillight Not Working After Tekonsha Wiring Installation

Question:

I just installed my trailer hitch and wiring. Everything seems fine except that the drivers side rear tail light does not come on when the headlights are turned on. The brake lights and blinker works as does the backup light and flashers. This is only on the drivers side, the passenger side all is well. I triple checked the wiring connections and also the ground. As an experiment I disconected the trailer wiring and reconected the Vans wiring and the light worked just fine, I did this because I thought maybe my LED running light might have been burned out but this is not the case. I am really puzzled by this and could use some help or advice. My trailer light wiring part is: TEKONSHA 118534..... Thank you

asked by: Marshall S

Expert Reply:

Since you disconnected the wiring harness and everything works again it is probably safe to rule out the vehicle side being an issue. Typically a single light out following the # 118534 installation indicates a ground issue. Although I know you already checked the ground connection, I would check it one last time. The ground should be secure on a clean, bare-metal surface. You could also try moving it to a different location.

I'm not sure what your connection checking process is like so I will cover that as well. Typically with this style of wiring harness you want to unplug the connector and then plug it back in to make sure it is properly seated. This may have also been the cause of the light not working.

The T-connection design is fairly simple and should allow the signal to pass through. Although it is unlikely, if neither of these steps work there may be a problem with one of the connectors in which case you would need to swap out the wiring harness for a new one.

I have attached an installation video for your reference.

expert reply by: Robin H