Troubleshooting Wiring Harness with 0.5 Volts Between Ground Pin and Other Pins

Updated 11/13/2017 | Published 11/12/2017

Question:

I have installed the harness on my 2014 highlander and noted there is always a small voltage 0.5v between the ground pin and any of the other three contacts. Even when the ignition is off. Voltage dissapears only when I remove the “towing” fuse under the hood. I am afraid The battery will soon die due to this parasitic voltage. Is my harness defective? Thank you.

asked by: Vladimir S

Expert Reply:

I reached out to Curt about your # C56217 harness and the .5V that you see on your harness is completely normal. There has to be a small amount of power going to any circuit protector to work properly, so that minimal current isn't even enough to light a bulb. You won't have any issue with starting your vehicle at any time even in cold weather due to that small draw.

To put it in perspective, the LED light on a cell phone charger that isn't connected to a cell phone will have more of a draw than that. Your harness is not defective.

If you really want to get rid of the reading on your 4-way, the only way is to install resistors in line to remove that voltage.

expert reply by: Jason S