No Taillights, Running Lights or Gauge Lights (K5 Blazer)

[DJ31499]

Hi all, I just picked up my first Blazer a few days ago and I've run into a few issues with it so far. It's a 1990 K5, 5.7 TBI V8, and I'm having an issue getting the taillights, running lights and gauge lights to work. I did some research and saw that people said to swap out the switch for the headlight knob, and to also check the tailgate area for open wires that might be crossing, broken etc. I swapped out the switch for the headlights today, didn't seem to fix the issue. Also checked the tailgate, everything seemed to be in order along with checking each of the fuses on the panel. They all checked out with a tool my buddy had that checks for the grounds and contacts. I'm brand new to a lot of the GM stuff coming from a Jeep, so I'm at a loss on what to do next. Any help would be greatly appreciated, trying to get this thing road worthy!