Trailer Lights Strange Behavior

I pulled boat out of garage to park on street before heading to the lake. I always turn my blinking hazard lights on and noticed that my side clearance lights and my reverse LED white lights (that came with the trailer) where all blinking as well. The trailer back left was NOT blinking but the back right was blinking as it should. I also noticed the LED white reverse lights were on even when not in reverse and no hazards turned on.

I turn my trailer tongue to store my boat in the garage. When I stored boat Sunday, I checked this plug. Everything seems tight. No nicked wires of any sort. I have my hydraulic lines and wires spaced so there is not tightness or hard pulls of any kind when turning tongue.

Where is a good place to start for a guy with little understanding of this? Truck or trailer?

2017 Cougar Trailer
2018 Nissan Titan tow vehicle

Thank you

ground wire maybe? bad grounds make weird things happen like wrong bulbs flashing. do you have a swing tongue. lots of wires break at the bend? check for a good ground from vehicle or try another tow vehicle to rule first one out? can run a ground from vehicle to trailer and see if it helps? jumper cable from truck frame to boat trailer?

Like Mike said above, bad grounds can cause a lot of problems. I used to carry a ground wire with 2 clips on it. Clip one on the truck and one on the trailer to see if your problem goes away and go from there.

If attaching a ground cable between the vehicle doesn't fix the problem and you don't have access to a DVM get a 12v test light probe from an auto supply store . Disconnect the trailer plug from your vehicle and prove the vehicle trailer plug output pins for proper operation with the test light ( marker lights ,L/R turn signals , brakes lights , and emergency lights ) . Link below is for a 7 pin trailer connector pin out diagram

https://tse3.mm.bing.net/th?id=OIP.P...=0&w=342&h=165

I know this was an old thread I started. Thanks for your help. But I ended up figuring out the issue before having to try some of the stuff mentioned.

I have to turn tongue (open trailer) to fit it in garage. I pulled off the black sock wire covering in the immediate area underneath where I pull the center pin to open trailer for storage. After removing the sock, the wires were flattened and copper was exposed. This had to be caused by me smashing them with the center pin upon inserting it to prepare trailer for towing. I had just enough space after cutting out the bad wire and recrimped with good heat shrink crimps. Good as new. I also bundled all the wires neatly in tubing and zip tied it all to the hydraulic line. Everything curves out of the way of where that center pin will come through.

Something you guys might want to watch for if you break your trailer to fit in garage. I know it's common sense but don't assume they stay out of the way.