My Grandpa and I are trying to fix a 2002 3

We are suspecting the computer may be bad, A friend of ours who works on Fords told us to check the fuel pump relay and starter relay, I dont really know why, My Grandpa is the one with all the information. He is a mechanic, I am just helping out. The one that isnt working did spark.

Well we cant get the engine to turn over at all now. Its like it went dead after the incident with the relays. It is like that plug for the starter is not getting any power at all. The fuses were okay according to my grandpa. The engine will not turn over, We put all new spark plugs in, they had spark but my Grandpa says the fire is week. However we cant even get it to turn over now, We are trying to solve this problem with the relay plug not having power right now. We checked the fuel pump plug with a wire, The fuel pump will kick on when we do this, But we cant get that starter relay plug to do anything at all.