2002 s10 wont start

My cousin has a 2002 chevy s10. It wont start we put a new fuel pump in it they told him it was bad and a new relay. It still has no power to the fuel pump.Gas guage will move with the key off but as soon a you turn on the key it goes to empty. We was told to check the grounds but dont know where they are located plus he was told it could be the ingintion switch. If you spray ether in it will start. Any suggestions on what to do. Or what else to check thanks

Ignition switch sounds like a good start. It is a typical player in the no start condition.

if starting fluid makes it run, then it is definately a fuel issue. can the pump be heard running for 3-4 seconds when key is turned on? is there any fuel getting to the test port at all? would really suggest getting a wiring diagram and going through it.

no pump dont kick on no power to it or the relay thanks

In the underhood fuse panel, next to the fuel pump relay, there is a recessed, single, empty terminal. That terminal goes directly to the fuel pump. When the ignition switch is turned to the RUN position, it should show battery voltage for 2 to 3 seconds, then shut off. If it does, the relay is working and sending power to the fuel pump. Installing a 10 amp fused jumper wire from battery positive to that terminal, the pump should run continously. If not, check for battery voltage and ground at the fuel pump connector on top of the fuel tank. Fuel pump feed wire is grey and the ground wire is black.