Wiring harness question from noob

[Hooligans01]

My tail lights, brake lights and turn signals on the tow vehicle work. I attached a 4 way trailer lighter tester to the tow vehicles harness. As stated the tail lights, running light, brake lights, and left turn signal are operable. The right turn signal is inoperable.

[carringb]

1) Verify the tester, make sure the problem isn't there.
2) Check the trailer turn-signal-fuse in the power distribution box under the hood. The trailer light circuits are protected separate from the van's lights.

[boywonder]

Originally Posted by carringb

Verify the tester, make sure the problem isn't there.

If you have a multimeter check the connector with that; that will confirm the issue is on the vehicle and not the tester.