Ok here's my problem. the other day my truck won't start. so I figure it was the battery. nope. I then notice my ground wire on the post was lose. So I tighten that up. Still had problem starting. So I replaced the bat post, clean the post. Well I still have problems starting it. So I figure out the neg wire where it's grounding to the fire wall looked bad. I clean the wire and scrape the area off. Well the damn thing still won't crank. What I can do is, take my jumper cable and connect it to the neg side of batteryt and ground it to the alt. Why is this a better ground than say on the side of the fire wall. Where are your'd grounding too?