Friend had a pop-up trailer for years. So trailer is probably 20+ years old. Gave it his sister five years ago, who used it a few times and stored it in her garage. Tail lights were used up and stopped working, so his sister had an idiot friend replace them. Idiot installed them onto a plastic surface with no ground, they NEVER TESTED THEM, then stopped using the trailer. So my buddy decided to deliver it to his other sister in South Carolina. Guess what -- lights don't work. It is 6:00 and he leaves the next day. I hustle over there, figure it out, run a ground, and sooprize sooprize sooprize they now work. Almost. Taillights work with headlights on. Brake lights work with headlights on or off. Blinkers are non existant. I had to hotfoot it outta there, so I told him to wire the other side and neaten it all up. Same result on the other side. He ended up driving to SC with no blinkers the next morning, so not my / his problem now. But still, I want to know why the blinkers didn't work. Connection is a flat five. All seems right. Truck is a 2015 Dodge Ram diesel. Lights on pop-up trailer are surface mount aftermarket. Is this a new to old compatibility issue? Wrong bulbs? Wierd light that needs two grounds, not one? Why no blinkers?
First question is . Are there amber lights on the truck for turn signals and Seperate brake lights on the truck . ???
That truck will have a completely separate circuit and harness all of the trailer lights- nothing is intertwined between the truck and trailer lights besides the switch. My first guess would be to check the fuses. I've seen more than one truck with the trailer fuses not installed from the factory..
Not sure how the 5 wire plug is designated . Didn't know why you needed 5 wires The 4 wire plug is : 1 = ground 2 = tail lights 3 = RS turn signal 4 = LS turn signal The truck probably has the 7 terminal round plug . I know there is an adapter to change it to the 4 wire . Don't know if there is an adapter to change to the 5 wire .
My 2003 Suburban had the fuse missing but that was only on the 12 volt supply to the 7 pole round plug for the trailer brakes battery . Never seen the turn signal fuses missing from the factory . But it is a Dodge .
I rented a 2020 Ford F250 that would blow the trailer turn signal fuse if you plugged the trailer harness in with the truck lights on. Loved figuring that one out at a highway rest stop....
The flat five is: 2 wires to left side. 2 wires to right side. 1 wire as a ground. We will check fuses, but I think they are okay -- he tows a larger trailer regularly. Maybe he doesn't realize blinkers on that are out too.
So it appears that there are 2 separate wires for the tail lights . One for the left side tail light and the other for the Right side tail light .
