a fuse is blown...a main fuse while the fuel relay switch was replaced.i didnt get an owners manual when I bought it, now it wont stay started

did someone try to jump start it but got the cables reversed? Honestly should not be having any trouble unless you've got a weak, corroded connection from the black cable to the chassis ground....disassemble and wirebrush that connection for a full 300 amps cold cranking potential~

the thing is Bettye...the replacement fuse will blow the same exact way~ so we've got to find out what went wrong before fuse replacement....unless something drastic like wrong-way-'round causing quite a few complications...not just a blown main fuse, but alternator diodes burned...sensitive instruments which rely on good ground are snorched and never the same...it gets ugly if this has happened...is the only scenario.....major battery problem....speaking of which you shoud buy a new battery as they go bad after five years with the NO lead tin/antimony alloys these days~

and be sure to clean the end of the Black cable with the wirebrush to bring it to maximum power potential....and the place that it bolts to...as well----havin' a good day yet?~

okay, when you turn it to the "on" position not yet engaging the starter, can you hear the fuel pump circulating through the fuel rail? this means that you've got some fuel pressure~ the motor works because you replaced the relay, right?