Nissan Repair: nissan repair, oil pressure switch, nissan repair

Question
i dont have any voltage at the connector that goes to the fuel pump,nor at the fuse inside the cabin,but i have voltage at the seat of the relay for the gas pump inside the hood,and when i connect the pump to a 12volt source it works,any suggestion what to check next,i have an altima 97,2.4liters with 125 000 miles,and im doing this with the ignition on  

Answer
Juan,

Either the relay is defective or the computer that grounds the relay is defective.  You will have to trace the power back.  Now, from what you say I think the oil pressure switch is defective since the computer uses it to sense if the engine is pumping pressure.  No engine run equals the pump not working for safety reasons.  For now you could get a switch to ground the relay so the car will run.  But you will have to switch it off when you turn the engine off.