need help with my Hisun

I purchased a 2015 Hisun HS500 UTV used, and the only thing wrong with it is the fuel gauge does not work. When the fuel pump is in the tank, the gauge always reads empty. When I remove the fuel pump from the tank and manually move the float, the gauge works as it should. When the fuel pump is in the tank, it sounds like the float is hitting something in the tank. I checked the tank and there seems to be no obstructions in the tank. I figured the float arm was too long so I cut 1″ off the length of the rod and reconfigured the float. I put it back in and the same thing happens: the gauge shows “empty”. I have made sure the fuel pump is in the proper direction with the inlets pointing toward the driver side and the electrical connection is pointing toward the front of the vehicle. I eben tried turning the fuel pump 180 dgrees so there wuld be no obstructions. We don’t have a Hisun dealer locally and all the dealers away from here, including the plant in Texas, have no suggestions other than what I’ve tried. Please help.

Maybe the float absorbed gas and now sinks. Have you verified that the float “floats”?

it does float. i can look in the tank and see the float arm move left to right. it is a new fuel pump. this is the second fuel pump i’ve tried.

I am not sure how a fuel pump and the gauge float are related unless the pump is holding it down. If I read correctly the pump is not in the way of the gauge float. Is the gauge and float built into the gas cap? Is it possible that the wire leading to the gauge hooked up backwards?

It’s always easier if you post pictures

the wiring from the dash to the pump is terminated on the pump end by a plastic (molex) connector. it cannot plug in to the pump wrong. i suppose someone could have rewired the connector but that probably is not likely. i have attached pictures of the pump. i’ve considered the fact the wiring harness has a boken wire in it, but the gauge operation is solid when the pump is out of the tank. the other thought i had was the float arm was not making good contact to the sending unit on the pump when it is submerged in the gasoline.

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   wiring-harness.jpg
   

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   hisun-fuel-pump.jpg