Alternator works randomly

[whynotthinkwhynot]

I doubt there are any names I could call you that you haven't called yourself. I bet the next time you work on anything electrical in a car- you'll disconnect that negative battery terminal.

Have you checked to see if you definitely don't have continuity between the ends of the alt power cable? What got burnt when it shorted?

If you're referring to the 175a inline fuse in that cable, yes you can purchase something similar and cut out the old one. IMO, it wouldn't be worth it. What you'd save in money, you'd eat up in time, and likely pain and suffering. Not to mention you might cut the old wire just a tad too short and have to rig or replace after you spent a lot of time rigging in the first place.

[braineatingalien]

I looked more at the wire and it turns out it has a fusible link on it that was fried. I replaced that to get continuity through the wire again. The alternator did test out bad. So I got a new one and installed it. Everything works again!

I am not sure if all foci have a fusible link but on my 07 focus hatchback it was right above the power steering tank.

[whynotthinkwhynot]

They should, but I thought it was on the other end of the wire. Earlier Focis used a 175a fuse. All it is there is to prevent exploding the battery due to a welded short circuit. Without the fuse or fusible link, someone who didn't disconnect the negative terminal could cause the battery to explode if the hot wire was to short against the engine block and weld itself tight. You'd have super hot sulfuric acid and hydrogen gas all over the place in about 2 seconds. Exploding batteries are not a fun learning experience even if you don't end up dead or disfigured.