new to this, and needing help... 98 f150, v6 auto trans, have to bypass inertia switch to get fuel pump to run, its bypassed by going off black/pink wire on inertia switch pigtail to pos. on battery, already replaced switch with new, still wont work with just new switch hooked up, only with jumper wire bypass. have checked all fuses and relays and they are good, with it bypassed it runs and drives fine, unhook jumper wire and it wont start, if i leave the jumper hooked up, i hear a faint high pitch noise, im thinking the fuel pump is crapping out, but would like to know for sure before spending serious $$$ on something that i bought for just $350. any help or ideas are greatly appreciated thanks

 

From what you saying you are not getting power to the switch. This is not a quick fix.The PCM has a crank mode and a run mode to run the fuel pump. A quick thing to try is disconnect the switch and connect a test light to the power wire from the fuel pump relay while watching the light have someone turn the key to the on position (not crank). The light should turn on for a few seconds and turn off.if this happens the circuit is good if not try swapping. The fuel pump and horn relays ( most are the same type on fords) and turn the key on again if it lights reconnect the switch and see if the truck starts.if not you could have wiring problem or a bad PCM not sending a signal to the relay.This is why with every car and truck I buy I go online to Helms and order the shop and electric manuals.just keep one thing In mind touch to wrong wire at the wrong and you will fry a 900.00 dollar PCM