You did not mention anything about Fuse#31 which powers the tail light and instrument lamp fuses. These are the only two fuses connected to #31 in the 96 diagram.
That's more what I was driving at. The OP may not presume to walk around the back of the car if the dash/running are out. No power to the first mentioned fuses may be fed from an upstream block fuse. That's what I was half-conjecturating from the thread I linked up there.
Final thought - I'd be hunting slightly earlier work on the car that may have messed up a ground, or, find those upstream fuses/breakers/relays whatever, v. zooming in on the switch. Sure they go bad, but unless some special abuse/overuse the other stuff's more probable.
\'96SS SOB: SSRI, Herter Tune, Tri-Y II, , 3000 Edge, F/HO bars, METCO extendeds with CV MMC, Bilsteins, currently Vredestein Ultrac Sessanta (315/35 rear). Finally, wait for it... LT-4 knock module!
\'96FWB BUW-Butt Ugly White: PCMPerformance tune, HDFA w/ swissed filter, 1/2 SLP s.s. catback with H- and Flow Super 50s, oem opti rebuilt 3 times, SS Bars, METCO LCA, Airlift 1000, Monroe SS, PowerTrax No-Slip, CTS wheels with +1 rubber. Finally, yes again... LT-4 knock module!