when im sitting in the truck it's the right taillight
From the diagram it appears you may have two white with yellow circuits back there the L70 and the L62, then double check to make sure the white and yellow you are talking about does not have power when you have that turn signal on, if it does, you are chasing a ghost.
o.k. this should not have brake lamp feed, it should only be the white wire with the light green tracer that runs brake lamp feed.
the white with green wire
O.k. check it out and let me know, tell me anything else you find, the next time i will be on is later tonight, around 9:30, let me know anything else you find so we can try to figure this out.
pin 12 pin 27 nothing
30 31 at 0
O.k. so basically what you are telling me is that you have an open connection at those circuits, you should be reading some resistance, but if you are reading the same as if you have the electrodes of the ohm meter connected to nothing then you have an open circuit.
This has me thinking if you are not experiencing a short in that fuse box, basicaly what is happening is the overhead is dropping power as if it was a battery disconnect every time you turn the key. you may want to pull the overhead down, and examine the harness there, and see what power drops off with a test light, or see if there is a circuit going to it, that is neglecting to give it power at all.
You would have no brake light on the other side either, have you checked the output at the fcm?