Sometimes it is a ground problem. I have fought terrible battles with wiring only to find that it isn`t grounding. Get a test light or a multimeter and get ready to have some fun. Also, there may be a breaker. I am not that familiar with the newer vehicles. Test backward from the trailer plug, isolating the hot wires to your tail lights. And last but not least, check the bulbs.
trace your ground wire around and through your frame, starting from the tail lights to the front , sounds like the ground is shorting out somewhere .
speaking from experiance
Check both bulbs, if not that, check the wires near the trailer plug.
Check the ground wires or the bulbs may be burned out.
you might have a bad ground some where. Your trailer lights might be grounded separate
Check all the ground wires.
9 times out of 10 its a ground wire.
Sometimes it is a ground problem. I have fought terrible battles with wiring only to find that it isn`t grounding. Get a test light or a multimeter and get ready to have some fun. Also, there may be a breaker. I am not that familiar with the newer vehicles. Test backward from the trailer plug, isolating the hot wires to your tail lights. And last but not least, check the bulbs.
trace your ground wire around and through your frame, starting from the tail lights to the front , sounds like the ground is shorting out somewhere .
speaking from experiance
check the bulbs