@nox - what units are you asking about? I'm confused.
No offense taken, I'm starting to lean towards letting my usual mechanic take a look at it. I'm far handier with a wrench than a multimeter, but do have a grasp on basic electronic repair, due to learning to solder to fix (or mod wiring scheme) guitars/basses. Diagnosis is where my skills lack. Gut tells me it's gonna end up being the BCM though.
Main troubles as of right now is the lack of interior lighting, fog lights, and blower motor running with key off. All of which, just minor inconveniences. I bought this as a second car anyway, to have something more fun, comfortable, and better mpg's than the truck. ['92 1/2 ton Chevy SWB.] Knew it would need some sorting out going into the purchase.
Everything appears stock, except audio system. There were left-over wires [remote on, ground, rca] to the trunk for subs, which i have now removed.
Oh! I followed the extra "mystery" wire from the DRL fuse the other day. Interior fusebox--> Door Jamb-->Under Hood --> is spliced into the wiring for the passenger side turn signal bulb. It's soldered into [i think the brown wire, iirc.] When I unplugged from fusebox and turned key back on, something in the dash started making a constant solenoid click, like a bad starter but not as loud. Couldn't pinpoint source, but definitely driver's side. Thinking back, possibly ignition related? Did not function check outside lights w/o wire.
At this point, i threw in the towel. Plugged the mystery wire back in, and decided to just leave it the heck alone for now. Switched focus to restoring the headlight lenses and a full int/ext detail.
Edit to add: forgot to mention, TCS OFF button and low trac DIC lights do not function either. Hazard flasher switch and shift-lockout-something are missing as well. Keyless entry does not work either, but have not ruled out fob as problem.