Gaa2008

When towing my jet ski trailer, which has a 4 pin harness, only the brake and turn signal lights work. None of the auxiliary lights all over the trailer turn on. Tested with a friends nissan titan and the lights all turn on. What gives?

CCR90

Have you used a multi meter or test light and checked your pins on the truck end ? Are they green from corrosion?

BlackKnight81

Check the brown wire on the 4 pin connector with parking lights on-
should have 12 v.

muddyz

Check your fuses under the hood too.