OP: Yes I'm still here. Thanks for the additional comments and thoughts.
On the grounds... The schematics i found show the lights grounded individually, but upon disassembling light fixtures, i found this not to be the case. I heard mention of a single ground causing similar problems.
F-250 2003. You lower the spare tire. THe ground is directly to port side of the spare tire winch on the inside of the frame. I cleaned it and it did nothing. But it was badly corroded.
The last couple days I have been trying to get the spare off. Ford has a security key on the spare winch to prevent theft. I didn't have the key (like a lug nut key), so I ended up using my dremmel to cut the wire rope that holds up the tire.
The flasher might be an easy one to try.
There seems to be a heating angle to this problem as if everything is cool, the flasher starts off correct speed, but increases with time.
I think next i will start with the night running lights and just get the voltmeter and do it the old fashioned way. Point by point working my way along the wire.
Here is another weird clue..
So looking at the schematic, there is the light switch that in running light position, allows 12vdc to flow to front running lights, rear running lights, and license plate lights.
Front running lights... fine.
License plate lights... fine (but dim and bright with blinkers).
Rear running lights.... off
If i can get some running lights, I will feel safer (from police) to drive at night. Right now the truck is completely black at night and I stick out like a sore thumb.
