1997 Camaro rs missing adapter to alternator

What replacement part? What kind of adapter? You only need a single wire, usually brown, in the plug, and the fat battery wire bolted to the terminal on the back, to make it work.

See below

I can't remember which terminal is the right one but if there are letters, (f, s, p, l), molded onto the plug, you want terminal "L" for the dash light.

Two of the other terminals are not used. Terminal "P" is only used on diesel engine for the tach signal. If there's no letters molded onto the plug or cast onto the housing, when you connect the car's brown wire to the correct terminal, the battery light should turn on when the ignition switch is turned on. You can do the same thing with a test light. Connect the ground clip to the battery's positive terminal, then touch the probe to the wires in the plug. When you touch the right terminal, the test light will light up indicating it's trying to turn on the system. At that point the generator will start working when the engine is running, and the test light will be turned off.

You can also just look at another generator on a car in any salvage yard or used car lot.