Is there more than one fuse for fuel system on 1990 Ford f150 pick up truck?
I assume you are talking about the relay.
ignition switch may be failing to send 12 volt to starter relay on fender well
Have someone behind the wheel. Turn the key to "start" check voltage at starter wire from relay on fender well. Check backward at connections backward until you get power. Probably the starter switch.
Looking for a Used F-150 in your area?
CarGurus has 183,734 nationwide F-150 listings starting at $699.
Search Ford F-150 Questions
Ford F-150 Experts
Related Models For Sale
Used Cars For Sale