I recently bought a 1994 Z28 which the cooling fans only come on with the “a/c” on, I was wondering if anyone else has figured out the solution to this problem?

 

test the temp sensor on the water pump. have a look here
4th Gen LT1 F-body Tech Articles

and here
4th Gen LT1 F-body Tech Articles

 

This has been discussed before, with factory programming, the PCM won't kick low speed on till about 226º and high speed on at 235º. Low speed will kick off at 220ish and high speed will kick off about 230ish. Center marker on the temp gauge is about 220. Fans should ALWAYS kick on when A/C is on unless at cruising speeds where they may be kicked off or if you have low refrigerant.

If your temps aren't getting any where close to the red while cruising or idling, then everything is working as it should.