Troubleshooting Diode Trailer Wiring Installed on Vehicle Where Turn Signal Flashes Both Sides

Question:

I have wired up a 2017 Ford Edge SEL using a 4 diode and one 50 ohm 10 watt resistor. Using Blue OX diagram BX88334. Everything works correctly until I turn on the tail lights running lights. When they are on and I use the turning signals, either right or left, both tail lights flash. What did I do wrong or am I following the wrong diagram? Need your help as We are about to hit the road heading for Florida. Thanks in advance for your expertise!!!

asked by: Tim M

Expert Reply:

It sounds like you have the turn signal and running light circuits ran backwards so that when either blinker circuit is activated you end up with both lights flashing. This is because the running lights run to both sides of the vehicle and the stop/turn circuits go to each side specifically.

expert reply by: Jameson C