Troubleshooting Interior Trailer Lights Not Working with 2013 GMC Sierra

Question:

2013 gmc Sierra All my trailer lights work , but the interior light in my stealth trailer does not work . I cant find an auxiliary fuse for this . The interior pics gut does work. It worked on my previous vehicle and other vehicles that have pulled that trailer . Looking for suggestions ?

asked by: Tim A

Expert Reply:

If the interior lights on your trailer are wired to the 12V circuit on the 7-Way I first recommend taking a circuit tester like # PTW2992 and testing this pin on your Sierra's 7-Way (1 o'clock position). Check to see if this pin gets power both when the truck is off and when the ignition is on. Many factory 7-Way connectors on trucks feature a 12V pin that is only active with the ignition on.

If you don't get power at all, whether the truck is on or not, then it could be a blown fuse like you mentioned or an issue with the truck's wiring. I took a look at the online version of the owner's manual for your 2013 Sierra and it looks like there should be a 40 amp fuse located in the #68 position inside the engine compartment fuse box. Check to make sure this fuse is present and in good condition, replacing if needed.

If you did get power at the Sierra's 7-Way then there is an issue with the trailer side connector or wiring. Inspect the 7-Way on the trailer for any corrosion or debris that needs to be cleaned out. Then try and inspect the wiring coming from the back of the 7-Way to your interior lights for any exposed or damaged areas, replacing as needed.

If you still aren't able to locate and resolve the issue please let me know and we can continue to troubleshoot.

expert reply by: Chris R