i have an 89 f150 with a 5.0 and the other day it was running fine, i drove it up to the store put a couple gallons of gas init and drove it home and parked it, well 2 days latter i get in it to go to the store again, well right before i start it the fuel pump kicks on for about 2 seconds and then i ussaully crank the key and start the engine, well i didnt here it kick on im not sure what happen i had the fuel pump and fuel pickup replaced last summer. one of my friends said something about a fuel pump relay? i checked all the fuses thinking it could of been a blown fuse. im lost and would appriciate your help

 

The click you're used to hearing is probably the fuel pump relay which is just a switch used to handle the current demands of fuel pumps. If a relay goes it doesn't necessarily blow a fuse. If you know how to use a voltmeter you can check the relay, if not, relays are not too expensive you could gamble on the price of a relay to see if it solves the problem.

 

I would also check the wires running to the relays. Thats what happened with my '88 one of the wires were so corroded I had to chop like 2 inches off and put a new plug on it. Then it worked fine.

 

Does an '89 have the switch that disconnects the fuel pump with an impact? My wife's 5.0 mustang ('92) had it, and slamming the liftback would set it off.

 

There is an inertia switch located on the inside firewall, about 6 - 8 inches left of the steering column.

There is a magnet that holds a ball in place which does its magic on impact. Pretty slick device - a web search can show how it works. The reset button is on top, kind of in a recessed plastic sleeve.

The fuel pump relay is in the engine compartment on the driver side fenderwell in along side the test port connector housing.