I would start by inspecting the entire length of the rear lighting harness. You don't have to tear into the harness loom. Just do a good visual check of the outside (corrugated) sheathing. The four leads that comprise the rear lighting circuits (YEL = LH T/S & Brake, DK GRN = RH T/S & Brake, LT GRN = B/U, and BRN = Parking, Marker & Plate lighting) are encased in a length of very durable plastic tubing. In addition, that tubing (along with the PNK lead to the gas tank sender) is encased within corrugated loom - for about half of the total run. The outer (corrugated) sheathing terminates when it emerges from under the cab. At that point, the PNK lead is connected to the sender and the hard tubing - that contains the rear lighting harness- transitions from the outside of the frame rail to the inside.
While tracing the harness, look for indications of exposure to high temperatures (i.e. melted areas of the plastic sheathing) and verify that it is not being pinched/crushed between structural components.
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
The most likely spot for heat damage to occur is where the tubing transits close to the exhaust system - pay particular attention to the section that runs alongside the muffler (if you have a muffler on the LH side):
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
After passing the muffler, the harness is fairly safe:
You must be registered for see images attach
You must be registered for see images attach
To do a shotgun test of the branch leads and associated sockets, locate the Weathertite style connector on the after side of the rear crossmember and disconnect the plug/socket. Try the directionals, brake lights, hazards, etc - whatever you are having trouble with (sorry, I didn't view the video yet). Of course none of the rear lamps will be working with the harness unplugged, but observe the front lighting group. If everything up front functions normally, you can concentrate on the rear lighting Christmas tree.
I would do this check first - it may save you a lot of time searching for a problem that doesn't exist.
You must be registered for see images attach
The rear lighting Xmas tree layed out:
You must be registered for see images attach
I have one strong suggestion - until you have found and rectified the cause of these issues, lose the LED's and return to incandescents.
You are going to confuse the issue by introducing an unstable variable during the diagnostic phase. Installing those LED's did not solve the underlying problem, it only altered the way in which in manifests itself. Get everything back to normal and then make the switch to LED's if you still want to. Just my thoughts.
As far as this:
So today I replaced the front flashers which didn't seem to fix it other than they are brighter now and my stereo started working
What do you mean by "replaced the front flashers"? Do you mean the 1157 lamps in the parking/direction assemblies?