Cadillac Repair: 1985 Cadillac Deville, oil pressure switch, fuel pump relay

Question
My car started good and then my husband filled up the tank.He drove home.When I went to start up the next day it would not start.Would it be my fuel pump and if so how do we check it and where is it located.Is there andthing else we could check for?We are trying to get a book on the wiring and etc.Thank You  

Answer
Hi Linda, It is amazing how many times a fuel pump will fail after it gets a cold fill of gas on the warm or hot pump. It is located inside the gas tank. If the fuel filter hasn't been replaced in 2 years or 24,000 miles try that first but it still may not start. There is a fuel pump relay and fuse as well as oil pressure switch that control the pump operation and they need to be checked. If the pump hasn't been replaced yet then it is probably bad. What I do is unplug the connector back by the gas tank and use a 12 volt test light to test for power to the pump. It will have power for 2-3 seconds after the key is first turned on and then shut off. If that happens then the pump is bad. If no voltage then the circuits will need to be checked to find out where the problem lies. Hope that helps. Bill