Welcome to the seadoo forum highkick. You are correct that the oil sender is a different sender than the fuel tank guage. I would add oil to see if it goes off. It is just a low oil indicator light. The sender in the oil tank works on contact of oil on it. I would also check the connector just above the oil tank to see if the wires are connected ok. It could be dirty connector.
For the fuel tank sender, you need to check the Pink and Pink/Black wire coming out of the baffle tube in the gas tank. The sending unit works off resistance. Pull the plug apart at the tank, and use an ohm meter to check for resistance between the two pink wires. The resistance will be different depending on how much fuel is in the fuel tank. If you get no resistance, remove the clamps off the sender, and pull the sending unit out of the fuel tank. Check the magnets on the float in the sending unit. To get to the float out, pop the bottom off and look for the 4 magnets on the float. If they are missing use a strong magnet to get them out of the tank bottom. If they are dirty clean them and re-insert it back in the baffle tube and check the wires again to check for readings of resistance depending on where the float is in the baffle tube. If still no reading of resistance replace the sender. If you get readings, check continuity of wiring to guage. If all wiring checks out ok the guage is bad. Keep me posted on your progress.
Karl