So the truck has been doing this since i bought it and I'm not really sure where to start. The turn signal starts out slow then speeds up the slows down again. I don't know if it's an aftermaket flasher unit or just broken, but i don't like it. Im not exactly a newb when it comes to auto wiring, and a subject of worry is that when a previous owner put in the bed trailer connection, they T-Tapped it to the vehicle harness. However, I don't believe this to be the problem because the rate doesn't seem to change based off of bumps, speeding up, slowing down, or any combination of jumping or pushing. Any Ideas?

P.S. The 4 ways work normal and constant.

 

try replacing the flasher. the 4 ways run on a seperate flasher that sits on the back side of the fuse box under the dash. or try swapping them and see what happens.