Troubleshooting Trailer Lights Not Functioning when Using an Aftermarket Flasher Unit on Trailer  

Never had a problem for years and now I do. 2003 GMC Sierra factory trailering package with 7-way plug. What is happening and then what I did to try to solve the problem What happens: No I have had a little module from superbrightleds.com that makes my LED trailer lights flash like 5 times in .5 seconds, then 4 times slow, then stays red. Never a problem. None. Have them on my line of fine led strips on my trucks, too. No problems. Recently, I checked before pulling and found no right stop or turn lights. What I have done: checked rear of truck in 7 way receptacle and have power to the right stop and turn terminals. 38656 junction box with the molded connector pre-wired. I connect this connector to the truck receptacle and have power to the terminal for stop/turn signal. I have an ohm meter and 12 volt test light, that flashes as the current pulses. When my turn/stop lights stop functioning.... and I take the flash module out of the circuit and just connect the turn/stop wire from the junction box to the trailer directly....I get the OEM flash. But, not with the module in place. NOW, the lights stopped and when I take the module out of the circuit.....and touch the turn/stop directly from the junction box to the trailer.....I GET an ARC, a SHORT. This has been a repeating problem. I get it fixed and then it recurs. I even re-pulled new wires on that side of the trailer. It was working last weekend and today, no lights and the short is back. I dont see how I could have a short with a trailer sitting still. I am about to disconnect my three LED tail lights on that side and recheck for a short. If still there, I guess I must re-pull wire. I just dont know. This is on one side and never before. ANY help or suggestions are greatly appreciated. I have bought a lot from you as you have great products, great prices/shipping and seems like great help. It is just frustrating, but there has to be a short with a cut or abraded wire, I guess. Thank you

asked by: Dr. M