fuse

every time i try to start my truck the fuse blows.
i lost my owner manual in a fire, i do not know what the fuse goes to, its a 20 amp fuse in the power distribution box. please help!

So does the truck continue to run? Will it blow the fuse if you just turn the ignition switch to "run" positiion? What doesn't work? look under the lid to the fuseblock- there should be a detailed diagram there for what the fuse protects.

no the car wont turn over, the lights and radio work it just blow the fuse it happen last week, i replaced the fuse and the car started up, now the fuse just burns out everytime i replace it. i replace it 3 time.