2010 Chevy Express Collins Bus Help

[jsmonty]

We are in the process of upgrading our tailgate but to a more reliable and easier to drive/park/manage 2010 Chevy 1ton collins school bus. All of the Chevy functions are good to go however working through the Collins wiring has just given me more questions than answers. A few of our switches do things I wouldn't expect them to be doing and when tracing wires vs the wire diagrams I have found they don't match up. Is it possible when they pulled systems out of the bus before sale they just plugged stuff in randomly?

I've uploaded some photos, I think the clearest example is on our electrical panel above the driver we should have an orange "mast-pw" wire on fuse 7 however when we look at the bus its connected to fuse 9 which is for a red "ext-pw" wire out of the harness.

Appreciate any help or ideas before I tear into this thing

[Jolly Roger bus 223]

text me with a skoolie reference at 910-581-7210 and i can share what photos i have of that area in my 04 chevy collins.

[cadillackid]

the board on the right with CR, CLR etc is your carrier air conditioning system, leave that alone unless you like to sweat while driving..

[jsmonty]

Originally Posted by cadillackid

the board on the right with CR, CLR etc is your carrier air conditioning system, leave that alone unless you like to sweat while driving..

That was our plan, haven't had AC prior so it wasn't a big priority but trying to get everyone else "on" I used another ignition trigger to enable that sides relay and once powered switches began doing "different things" than they did with that side not powered on which is when I stopped messing with everything and decided to post to the group for ideas.