Troubleshooting Trailer Light Fuse that Keeps Blowing in a 2016 Toyota Sienna

Updated 10/08/2018 | Published 10/06/2018

Question:

Fuse for brake controller i have a 2016 Toyota Sienna. My trailer lights work for a while but then i blow the fuse mounted to the battery. The size fuse that keeps blowing is 20 amp. Would increasing the fuse size to 30 amp solve the problem? Again, when the fuse is blown and then is replaced the lights work for awhile and then quit.

asked by: Bob

Expert Reply:

A 30 amp fuse will likely fix the problem of the fuse blowing but fuses are meant to safeguard against wiring overheating it would be dangerous to do so and could result in a fire.

It sounds like you simply have a short somewhere. Start off by checking the connector on your 2016 Toyota Sienna and your trailer. Clean out any debris or corrosion and apply some dielectric grease like part # 11755 to help keep them clean and protected.

If your connectors look good then you need to check the wiring on that circuit. Check for places where the wiring is damaged or bent and check the ground connections for your lights as well. Ensure they are securely connected to a clean, bare-metal surface.

If the fuse is related to the brake controller then you shouldn't be seeing that affect your trailer lights.

Attached is a helpful article on troubleshooting lighting issues. If the steps don't fix your problem let me know and I can help you troubleshoot further.

expert reply by: Jon G