Sonomas are decent little trucks overall. With a lot of Gm products a lot of shit quits working for no reason (or cheap plastic parts break) and there’s always little gremlins to chase, but they’ll usually get you to where you’re going.

But ya, If everything worked proper, the 96’ Sonoma is supposed to turn the ac compressor on and flip a vent door to redirect the air to your windshield whenever you put the dial to the far right defrost. It’ll still defrost the window anyway if the ac is bust, but with the dry air it works a lot faster. Your defogger button directly under that knob only puts power to the heat lines in your rear window. They’re kinda meh for actual defogging in my opinion, but they’re great for melting ice so you can at least see out the back.