I think the alternator is OK judging by the voltages.

 

It could be ok, I multi metered mine and every thing was ok, Grandads 00 F150 did the same thing he had the alternator checked twice and the battery changed as did i and we both got stranded due to a bad alternator. Its to easy of a test to find out if your going to be left on the road with a bum alternator.

 

I'm going to check all the grounds after supper.

 

Alternators are pretty rugged, but can succumb to excessive heat and overwork. They can also be damaged by sudden voltage overloads (as when someone attempts to jump start a dead battery and crosses up the jumper connections or if someone disconnects a battery cable from the battery while the engine is running).
My old man who has been a mechanic for 40 years told me disconnecting the negative while running is one of the worst things you could do to an alternator.

 

Sounds Good! And im sure it is, but if its bad already which it looks like its not going to hurt. let us know what you find out tho im interested. Feel free to explain how disconecting the neg batt cable to find out if the alternator is dead is bad on any alternator because all's you are doing is taking away the ground......

 

It also causes the charging voltage to rise since the voltage regulator loses its reference and cannot regulate the charging voltage. The higher voltage and voltage spikes can damage electronic components.
That practice was more for the cars of old with no computers.

 

Now see that i can see happening....
But i will still use this 5 min method to find out the problem insetead of chasing wires grounds and evrything else. still let us know what you find out and how you did it.... have a good supper lol!

 

Doing the Neg cable trick is fine for the older cars/trucks. You can cause yourself problems on the newer stuff doing that. I would reccomend NOT doing that.

 

Drivers side ground standoffs on the fender were skimmed with body filler and painted over. I know that fender was replaced, but why the body guy wasted time skimming over the ground standoffs is beyond me. Sanded them down, cleaned and retightened all grounds and wallah, batt gauge rock solid just past midway at idle even with highbeams, fogs, 100w grill lights, 100w reverse lights and stereo pumping.

 

Nice! Glad you got it fixed, im going to think over the next time on the neg batt cable unless things just get deperate! But with this new alterator better hang on lol