Hello everyone, back again

i am having an issue with the factory trailer wiring in my truck, here are the symptoms, when i have my trailer plugged into the truck all the lights light up as normal but the right light on the trailer is very dim, when i turn on the left signal it works normal but when i use the right signal they both blink, and here is the kicker when i turn the truck completely off turn off all lights and everything the rear left light stays on in which i have to unplug the trailer to avoid my battery dying.
i have checked the fuses in my truck i have plugged in a friends trailer to my truck and it has the same symptoms as my trailer so i am positive it is my truck, i have used a test light on the electrical plug on my bumper and one of the prongs is on even when the truck is completely off and i don't know why, all i could think of is it could be my clearance lights on the roof of my truck i installed myself on my ram 1500 but i unplugged them completely and learned that it wasn't the problem.

any ideas on where to go from here?

 

My guess would be that somewhere in your factory wiring you have wires that are touching each other or touching metal. You might want to check the connection you spliced into you tow wiring for your cab lights. It sounds like you have a constant live feed thats touching your left tail light in the plug. That makes me think that the problem is between your plug and where your factory tow wiring connects to your actual lights in the truck. It could also be a bad ground but I wouldn't bet on that. Make sure connectins are clean where you plug your trailer into. You could have an issue in that part on your bumper (plug) inside being bent or broken. Take a tester light with a needle tip and poke your wires behind the plug. Basically follow it back till you find out where the problem begins.

 

its just your simple wiring troubleshooting. Sounds like theres a loose ground or possibly a short. First check the grounds. Next, use your tester and find each faulty wire. trace it until you find a problem with it. my guess would be loose ground though for sure