Freightliner and Western Star are both multiplex, SAM module, anything in those years and up that had Mercedes power was multiplex.
The SAM can have a multitude of operations to perform, other than just lights. Unless you have a wiring diagram from the serial number
it can be a chore.
That 4090 had been setting in one spot for 34 years, right along with everything else around that place. The guy who owned that
4090 had a string of scrap reaching 1/3 of a mile long right over a buried water line that he was in a feud over with the county.
He is a fellow who doesn't believe in...
I thought about and had a line on a good running 12V71 to put in the B75. With adding 14" to the length of the hood there was plenty of room.
But one big problem with that was the radiator, having a cast aluminum top and bottom tanks and the fact those are hard to find I wasn't ready
Hooked up air compressor to dryer, fuel system, power steering hydraulics and built belly strap/brace under transmission. And set radiator plus hooking up cooling hoses now.
Will install headlight buckets and lights plus run wiring.