Weird OD problem
My truck wants to not go into overdrive. When you turn the ignition on the OD light is supposed to be off. Mine is on. It will sometimes shift into od. It has to be electrical. I check for codes with a MT2500 and none. When I did the KOER test the light will go out. I have did all the usual stuff, the shifter wires, took the chip out, took the transcommand out of the loop, everything but this has me stumped. It shifts fine 1-3. I have checked the wiring and can't find anything. When it finally decides it wants to shift into od it will work for a while then when going down the road it will shift out on its own and sometimes you can push the button and it will go back and other times it wont. Can someone jog me to make me think of something that I haven't done?