I pulled my instrument cluster out to replace the bulbs and found out why things didn't work, there was some heat damage and broken traces. I repaired the traces and I wanna bench test it before reinstalling because it was a beast to remove.

I know how to do the fuel gauge. Water temp, battery and speedo, but what do I need to do to test oil pressure and the tach? I've seen people say i need a waveform generator.