Hello,
I'm new in the truck world (and forum world too haha) and I just purchased a 1999 fort f150 ext cab 4X4. it's got some electrical issues, but I cannot figure them out! here's the list of issues, and of what I've done:

Issues:
Radio doesn't work
horn doesn't work
fuses blow quite often

What I've done:
Check every single fuse in both fuse boxes (not relays, idk how to check them)
replace blown fuses with correct amp fuses or higher amp fuses
checked radio fuse (aftermarket radio has fuse in back)


Please help!

any help will work,

Thank you!