T-Connector Trailer Wiring Harness Keeps Blowing Brake Light Fuse on 2007 Toyota Sienna

Question:

Bought this part. Blows my brake light fuse. Thought part was bad got sent another one. Still blows the fuse. Its grounded but still wont work. What could I be doing wrong? My trailer is brand new. Hooked the trailer up to my buddies truck and all the lights work. Thank you and have a nice day.

asked by: Abram

Expert Reply:

It is possible that the trailer lights have more draw than trailer wiring harness # 118304 can handle. It is rated for 2.1 amps per side for brake lights/turn signals and 4.2 amps for running lights. Your friend's truck is likely rated higher so it can handle the draw.

If this does turn out to be the problem then switching to LED lights would solve the issue.

The other option, since this is a recurring issue, is to replace the T-connector harness with a universal, powered harness that does not require splicing, # 119250KIT. This kit has connectors that clamp around the vehicle wiring to sense current passing through and gets power for the trailer lights from the vehicle battery.

This harness is also rated higher at 4.2 amps per circuit for brake lights/turn signals and 7.5 amps for running lights.

expert reply by: Michael H