Preventing Trailer Battery From Backfeeding to Vehicle Battery on 2003 Toyota Land Cruiser

Updated 06/06/2022 | Published 05/31/2022

Question:

hello, I have a 2003 land cruiser. There is a known issue when towing an RV on this vehicle, it seems like the voltage from the batteries in the RV backfeed into the tow vehicle. when I turn off the car and remove the key, the vent fans are running in the vehicle when the 7 pin connector is connected to the RV. Do you know how I can fix this? I cannot find a TSB on this topic.

asked by: Arnold P

Expert Reply:

In order to make sure your battery does not backfeed into your 2003 Toyota Land Cruiser all you need to do is add a single diode like the Roadmaster # RM-690. This will install between the trailer battery and 7-Way and only allows power to travel in one direction.

expert reply by: Robin H