will not start cranks but nothing els on 2000 Mercury Mountaineer

change fuel pump relay safety swich still in down position disconnected in line to fuel filter turned on key no gas

Asked by for the 2000 Mercury Mountaineer
Pretty simple test > Test for battery voltage present for 2 seconds on both wires at the inertia switch when key is turned on .. (Test one of the wires for battery voltage - cycle key again to check the other wire) .. IF voltage IS present on both of those wires - no further testing is required ... Replace the fuel pump!!