i have a 91 ford ranger,i cant get it to run.the fuel pump dose not turn on when i turn the key.i tested the wires that go to the pump and it has no power i replaced the fuel pump relay and the fuses are good.i tested the pump by hooking it to the battery and it comes on and pumps fuel.i was thinking it might be the ignition switch.what else dose the ignition switch control?dose it have any thing to do with the spark? thanks