enblethen wrote:
Check the tow vehicle for a blown fuse. many rigs have fuses that protect the trailer connector circuits. I cannot tell by your profile as to what TV is.
If no fuse is blown, use a jumper from the pop-up trailer connector battery pin to the bad side turn signal. This should tell whether issue is in TV or pop-up.
+1 on this. Drove myself nuts for the better portion of an hour fiddling with bulbs and connections trying to get the lights on my utility trailer working before hitting up Google for a solution. I could see the truck signals flashing but couldn't get the trailer to work, so I assumed there was a problem with the trailer wiring. I quickly learned that my TV has separate fuses for the trailer output and was back in business shortly thereafter.