Running Wire to Battery for Installation of Curt Wiring Harness on 2005 Lexus RX 330

Updated 08/04/2017 | Published 08/03/2017

Question:

Hi I have bought a set to install on my car. There is a long wire in the package to be connected to the battery. This is very difficult job , there is no way to do it neatly unless opening all bodywork Is this really needed? The + line will be in the rear of the car at the lamps, cant they be used at that location? anyway there is positive line in the connectors anyway , why taking an extra line from battery? Please advise

asked by: Mohammad J

Expert Reply:

Many vehicles, like your 2005 Lexus RX 330, require a hot lead wire to be run up to the positive post of the battery when installing a trailer wiring harness such as the Curt T-Connector Harness # C55563. This is needed to protect the delicate wiring inside your vehicle. By pulling its voltage from the battery, if there is a short anywhere on your trailer, it will not overdraw the vehicle's wiring and potentially damage something. Any needed repairs on a vehicle's wiring system can be very expensive and may not be covered under warranty.

It is also important to keep in mind that this wiring harness, along with the others designed for your vehicle, have only been tested using the voltage from the battery as a power source. Sending power to the harness in any other manner will also void the warranty of the harness itself, so I cannot recommend doing this.

Depending on the vehicle, running this power wire can be a bit cumbersome, as you mentioned. Because of this, we have a detailed article on doing this very thing, which may provide some help with your installation. I have attached the article for your review.

expert reply by: Chris R