2011 Prostar Electrical fault

[Jprps]

Hey fellas, So like the title says my Prostar has an electrical fault. Whenever I shut the truck off it will beep 10 times and show the fault on the dash odo screen. If I open the door and close it, It will do the same 10 beeps. OR if I turn the sleeper light on, It will beep with the fault when I shut the lights off. Also My engine fan acts funny sometimes, Like it will creep on by itself at like 3\4 speed and when I toggle it on manually it will come on fully, Turning the switch off shuts the fan off for a couple of seconds and then it creeps back up. At first I thought it was a mechanical issue but shutting the truck off and turning it back on again resolves this issue.

Today I started at my batteries, cleaned and replaced a bunch of the battery link cables, made sure everything looked good and clean and put it back together. There was quite a bit of corrosion going on there. Then I went to the fire wall and took apart the 100 amp fuse terminals, replaced them, cleaned everything there and put it back together. I also took apart the ground terminals and did the same. The truck now seems to start much better and even seems to be charging higher than it was before (which is a plus) But the electrical fault is still there. I also replaced every single fuse in the dash to no avail. (although for a 9 year old truck I think it was time to do that anyway). SO i don't have diamond logic and was just wondering where else I can look. From what I read on here there are more grounds inside of the cab? maybe my BCM is on its death bed? At this point im not sure. Truck drives and behaves 100% other than that and everything works 100%. Thanks in advance my dudes!