1989 Ford F 150 with a 4.9L engine, fuel injection, sometimes when I turn the key on you can hear the eletric fuel pump charge up and the truck starts, but many times when the key is turn on the eletric pump does not charge up and the truck does not start, it has a new eletric fuel installed. The maintenance book talks about fuel relay, do not know how to locate. Any thoughts.

Yes, you want to remove the fuel pump fuse and the fuel pump relay (normally 5-pin), in the underhood fuse/relay box, and clean the contacts. Lightly coat the contacts with dielectric grease. Locations are spelled out in your Owner's Manual. I've seen major corrosion problems on older F-150 fuses and relays--so much so that current won't pass. Should be an easy fix.

It would be a good idea to, one at a time, remove and clean each fuse and relay. Gently pry each relay out. I use a special rubber-tip pair of pliers for removing these relays--they can be stubborn.