Friday I was cleaning my wife'* 2000 Mountaineer and stupid me left the key in the on position when I was cleaning the windows. Realized it seven hours and a dead battery later. I went to jump it in the morning and as soon as I put the key in the ignition I was met with loud honking like the security button was pushed on the key fob. I took off the jumper cables and redid it per the directions on the manual. Got it started once, but it died when I took off the cable. So I just bought a new battery since it was the original. Started fine, but then it was charging low and the battery light was one. Got out the volt meter and it was running around 12 volts, around 12.25-12.5 with the engine off. I was getting pretty much nothing at the terminal of the alternator. I ended up popping the weld nut on the negative cable so I had to replace that cable. Still no change. I've had no luck finding any fusible links. And I found a post on another site with things to try and one was to check the voltage of the fuses in the distribution box. They all measured the same as the battery except the alternator fuse and another fuse for the EGR and some other stuff. They were both near zero. They didn't look blown, but could they be bad?

I did take the truck to Advance on Sunday and they said the alternator is bad only producing 28 amps. The guy said the alternator should be fine for a little while, and the truck did run fine. I also drove it about 10 miles Monday night with the lights and AC on and no problems other than the battery light. But then I went to drive it to work this morning, and a mile from home the ABS light came on, and then it started accelerating badly. I turned around and noticed the tach wasn't registering anything other than jumping when I switched the lights off.

I'm hoping a new altnerator is the problem, but something is just telling me it'* something else. Anyone have any other advice? I'm not electrical savvy, just to warn you.

it sure sounds like an alt to me.

Nope, wrong answer! I found it! I've read a ton about fusible links, but couldn't figure out where one would be after searching all over in the wiring. But there is a spot where the positive cable and alternator cables bolt down at the distribution box that peaked my curiosity. It was marked 175A, so I thought it might be a fuse. Sure enough after searching on Advance Autos website, it did turn out to be a fuse. I thought maybe this is the mysterious fusible link (there is no mention of it in the owner'* manual or the Haynes manual I picked up tonight). I found out how to test a fuse, and as a last ditch effort before blowing $140 on a new alternator, I replaced it with a new one I picked up on the way home, and voila, back to normal!

that'* awesome news! Great job on diagnosing the problem.