Its a complete plug and play setup with relay. I don't believe that you have to drop the tank. I'll check the instructions and let you know. I never installed it so I'm not sure.
I don't have any instructions..... Now that I thinkaboutf it I don't believe it came with any instructions. From the looks of it you do not have to drop the tank. Racetronix Part#RX-SY-FPWH-G