I am helping my elderly neighbor wire his towing lights for pulling his small truck behind his RV. I have them wired, but both portable towing lights blink when using left or right blinker [with the tail lights on]. With tail lights off the blinkers work correctly, left and right, work just fine and independently. Can some one set me straight? Do I have a “ground” problem?
Turn on just the tail lights. Is one light brighter than the other on the portable towing lights? If so, you have reversed the connection to the brigther light where you made the connection to the RV. If both lights are the same brighjtness, try replacing the bulbs in the towing lights.
Check this website for towing behind a motorhome:
Believe it or not there are multiple type harnesses for vehicles. Buying a harness in wally world may not work like the one bought from the dealership made for the vehicle. It sounds like what you did was hook a Turn signal light into the Parking Lights on one side.
Also if you go to a RV dealership and tell them the problem they, mine has, will probably pull up a wiring diagram and print it off for you.
Without a lot more info there is no way to be much more exact in an answer.
First thing to check is the ground.
Does the RV have turn signal indicators that are separate from the brake lights?
If yes, then you need to used a 4 light to 3 light converter in the trailer wiring to get combination turn/brake lights to work.