Troubleshooting Wiring Harness # 118482 on a 2011 Toyota Venza that Blows Fuses

Question

Question:

I am a repeat customer and have recommended etrailer.com to all of my friends who are in the market for hitches and accessories. I purchased a hitch Hidden Hitch and wiring harness 118482 from etrailer.com a couple of years ago for my 2011 Toyota Venza. The installation was easy and I followed your instruction to secure all wiring very carefully. However, I have recurring issues with blown fuse since the first time I used the unit. First I thought it was my trailer wiring and carefully inspected/replaced the wire. The fuse continues to blow within 30 min-1 hr of driving. I even increased the amp probably not good from 15 to 25 A and still have the same problem. I noticed that my trailer lights are always on and the brown wire is always active has 12V current. My questions for you are: Does the brown wire always carry current? Is it possible that the wiring module is malfunctioning? How many amp can I safely use without causing electrical problem for my Toyota? Sicerely. William

asked by: William H

1

Helpful Expert Reply:

The brown wire should not always have current on it. That is the running light circuit and is only supposed to be active when the running lights or head lights are on of your vehicle.

It is possible that the converter box is malfunctioning, what you could do is use your circuit tester to test the input side of the converter box to make sure that it is receiving the correct signals and then test the output circuits to see how everything is working. This will tell you if the problem is in the box. Chances are the box got shorted out from a short on your trailer wiring and now the box is malfunctioning.

We can not safely recommend you increase the fuse size from 15 amps. Toyota picked that rating for a reason and you may damage something expensive if you do not go back down to where you were. The Tow Ready Harness # 118482 that you referenced should only be using your vehicle tail light wiring as signal wiring and drawing all the power it needs from the battery with the power wire.

If the box proves to be the problem I would recommend you go over your trailer wiring looking for any shorts that could have caused the box to break and fix as necessary before you replace the # 118482 to prevent damaging the new harness.

I attached an FAQ article on trailer wiring that you should find helpful also.

expert reply by: Jameson C

1

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