Troubleshooting Battery Drain on 2011 Toyota RAV4 with Tow Ready Wiring Harness # 118412 Installed

Updated 04/26/2011 | Published 04/24/2011

Question:

I just installed a trailer wiring harness on my 2011 Rav4. It was a Tow Ready T-One harness. The harness works perfectly. Went away for a week and battery was completely dead. Again the vehicle is brand new and nothing was left on i.e. dome light or something I was wondering if the direct wire that runs from the battery to the module is drawing power even when the harness is not in use. The vehicle has sat for just as long previously and had no problems prior to the harness being installed. Thanks for your help.

asked by: Martin V

Expert Reply:

If everything is wired up correctly this Tow Ready Custom Fit Vehicle Wiring, part # 118412, should not be drawing any power unless the key is on or an accessory is attached that would draw power.

The only way this unit could drain your battery is if maybe there was a short on the power circuit that was causing the battery to get drained.

I would go over all of the connections of this unit and look for corrosion or loose wires. As long as this thing is wired correctly there should be no drain on your battery.

If you check the wiring and it looks good and you continue have this problem I would try removing the fuse from the fuse holder that runs to the positive side of the battery and see if that fixes the problem. If so, then you may have a bad tail light wiring harness.

I attached installation instructions and an installation video of this product below for you to check out also.

expert reply by: Jameson C