Signatures don't show up on a phone, sorry.

 

White he has a 2001 4.2

 

Had a 98 do this. Would up being the ground wire on the starter. Only did it on bumpy roads.

 

Is the yellow bat light blinking or is it the red?

 

It is a red light. Its not constantly blinking, its either on or off but in between it blinks here and there.
This morning when I was testing it was on solid and the voltage readings I got were ok, though I did not decharge like that guy mentioned in the video. I guess I can try again and post the readings if it helps any.
Where is this fuse exactly that was mentioned?

 

Just follow the main cable (Black w/orange stripe) off the alternator back, and you'll run into it.

 

You can do as has been suggested from jbrew, or white89gt and shake or follow the wiring harnesses and see if you can find anything that is sizzeling or loose. I have a '01 with a 5.4 and my experience is when the bat light is red that the Alternator is about to go dead. Twice this has happened to me. The first time the yellow bat light would go on a off for about 6 months, then the red light came on. When that happened it lasted about 20 miles before I had to turn things off so I could get home and install the new Alternator. The second time no yellow light, it went right to red. That time it only last about 15 miles before the computer started to turn things off, blower, radio, instrument cluster, before the engine died. I had the new Alternator in the back seat, oh well.

 

I replaced my alternator 2 years ago with a reman auto parts store job and since then the light comes on now and then. Never had any trouble with charging the battery.

Charging voltage is 14.5 - I was going to bring it back for a replacement but it works fine.

It's easy enough to remove the alternator and have it tested at the local O'Reilly's - would recommend you do this first.

 

So Ford Trucks are finicky about the alt. What you describe has been posted before and gone away when a Ford alt was used.

 

I'm ok with the light show as long as the battery is getting enough juice - the alt price of the alt alt was bad enough, don't even want to look at a genuine alt price.