Vintage Dodge Leaves Shop Owner....STRANDED!?! ('89 Ram 250 V8)

Got called in by a shop to diagnose this old Dinosaur: a 1989 Dodge RAM 250 V8 plow truck! Shop owner says that it was in for some lighting and wiring repairs. He took it for a short test drive after the job was done. A mile down the road and BOOM the old Ram STALLED out and never started again! He had to ask a friend to drag the truck back to the shop....where it's in a BEACHED WHALE state. Let's start from the basics, and see if we can get the old Beast running using a wiring diagram and a test light...Any Parts Required? Also the owner says the Battery DIES overnight...this truck only has 10 fuses and 1 computer, so that problem shouldn't be too hard to figure out :) AstroAI Digital DC AMP Clamp Meter: https://www.amazon.com/dp/B08MTCMWLB?... ATD Tools 5513 Heavy-Duty TEST LIGHT: https://www.amazon.com/dp/B000M5ZWBA?... TOPDON TORNADO 90000 BATTERY CHARGER: https://www.amazon.com/dp/B09XV64Q49?... Enjoy! Ivan