I figured it out (for the most part ) the sockets were bad put new ones in and the tail lights work but now the turn signals don't work. The emergency flashers work sort of. (The front signals blink together but the rear ones alternate back and forth) but not the individual signals (I'm thinking bad flasher now)? And I got some pictures I'll try to upload them

Also I noticed a solid red wire that was cut and taped off? And a solid black and a solid white wire that were encased together that were also cut and taped off what are these wires for? Could they be for the brake controller?

 

Here's how the po tied in the trailer wiring

 

The sounds like the grounds that screw into the sheetmetal behind the tail light housings need some attemtion. Pretty much every strange lighting issue ive ever had was ground related. I always add a new ground wire from the box to the frame to help minimize issues. The other thing i thought of was did you wire in new sockets? The sockets available today are horrible quality, ive actually resorted to cleaning up originals (if saveable) since they are better quality.

 

I bought a new flasher and voila everything is working

I cleaned up the wiring and took off the miles of electrical tape (I really hate that stuff) and also installed my new tail light housings so I'm definitely a happy camper

 

If I were you, those 3 way splices need to go too. Those stupid things are a huge path for corotion and cause shorts.

 

Yea that's the first thing I did. I don't plan on towing with my truck so I just took the trailer wiring right out

 

Those wire taps should be banned!!!!

 

That and there should be a limit on the use of electrical tape

Really cruddy connectors and the tape really gets my gears grinding . I soldered/ heat shrunk as much as I could. For some of the hard to reach spots I'm going to get the connectors that you crimp and then heat up afterwards (I'm not sure of the exact name of them)