98 Neon No Start

98 Neon, 2.0 engine....fuel pump wasnt coming on so I pulled into the shop and after an hour or so it turned on when the key was on...I pulled it outside and drove to the gas station and as I left it shut down again....no fuel pump.. It has been below zero so I thought maybe I had water in the fuel and it was freezing so I put a can of heat in it and towed back into the shop.. I left it in there overnight at 70 deg in the shop and this morning I still didnt have any fuel pressure....the pump did not come on with the key turned. I checked all the grounds I could find, checked the relay, (swapped with horn relay) checked the fuses.....nothing....Im not so sure it is the pump itself, I never had a fuel pump work intermittently before.. any time I have lost a pump, they just quit period.. This one has come on and off a half dozen times untill now, it wont do nothing....any Ideas? im at a loss... I disconnected the battery so I lost the check engine code, all I get now is a 12 and 55, 12 being the battery has been disconnected from comp in the last 50 cranks, and 55 being end of engine error messages....

Do you have an access panel for the fuel pump behind the seat, or in the trunk?

Do you have an access panel for the fuel pump behind the seat, or in the trunk?

nope, I can see where the fuel pump goes into the tank right behind the right rear wheel, I found I do have voltage to the fuel pump with the key in the on position, so im leaning towards fuel pump...

O.K., Broke down and installed new fuel pump.....WAY easier than I expected, I didnt even drain the tank, just unscrewed the fill tube from the car, taped off the vent lines then dropped it down. Slid out from under the car and stood it on end to replace the pump. Long story short, it runs again..........