If Vehicle Headlights are Set to Auto Will It Light Up the Trailer Lights

Published 10/22/2014

Question:

will trailer lights work if headlight switch is on auto

asked by: William R

Helpful Expert Reply:

As long as the auto mode for the vehicle headlights energizes the same running light circuit that is used by the tow package wiring running light circuit, then yes, it will work. To check if this is the case you will need to set the vehicle lights to auto, probably at night so the head lights come on, and then use a circuit tester such as # 40376 to test the vehicle side trailer connector to see if the running light pin is energized.

expert reply by: Michael H