Headlight work running tail lights do not have replace fuse after fuse and can't figure out what problem it as soon as i put a fuse in it blows it can u please help me figure the problem out

You have a short the short you have is a taillamp socket short. so youll have to inspect the tail lamp socket and acess the light. when you open the lights youll see where the lights go in they are very prone to touch together and take out the fuse.tail light socket short are common on GM and I know this is Isuzu but they use the same part.