Welcome from Winnipeg & I'm thinking a ground issue for everything to go kaplooey at once. Maybe the ground under the fuse box under the hood. Recently my blazer had issues & all the relays had + power & seemed ok, but a relay needs to have a ground for it to work. Check other sgrounds as well

 

New here too... I'm Kristy, bought a 1998 Blazer a couple years ago...used, it wasn't in bad shape, and had the requirements I wanted...almost brand new tires, 5 speed manual, and 4 wheel drive. Not sure if it's a ZR-2, there are no decals, but it has the 31x10.5 15 tires on it. With just over 80,000 miles on it when I got it, it now has 108,000.