I have a Cat c15 and no power to pins 52 and 53. Pin 70 shows power when key is on and the grounds are all good. For whatever reason the truck started fine until one morning the batteries were drained and i replaced all 4 of them. Now the truck just cranks and that’s it. Is there a fuse that I should check on the fuse panel. The fuse in the battery box for the ecm hot wire is good and it reads 12v on both ends as I probe it.
I am thinking I need to run a new hot wire to the ecm but am not sure if I run it directly from the battery or if it needs to be run from the fuse panel?