I hope not, I just paid $100 to have it refurbished .

I'll explain in a bit more detail. Please feel free to correct my errors or misunderstandings.

In the Excursion when just at idle with all accessories off I see 14.1 V reading through Autoenginuity and this reading on the load tester. All looks good.




Then when I turn on all accessories:

all interior lights
headlights - high beam
fog lights
A/C with both front & rear blowers on high (this is a big pull)
DVD player
Stereo
windshield wipers

I get a good drop........ 12.1 V on autoenginuity.



I did the same test with all accessories on in the F-250 and she holds just fine:

 

I am assuming it is the load and not the rebuilt alternator - but I could swap the two alt's and see if I get the same results.

edit: If I just run the front AC blower then it stays in the green, once I turn on the rear 2nd blower it pulls it down into the red. Another difference between the Excursion & the Superduties.

 

Rich, on that second photo from the top, I read 13.7 Volts...which is plenty if that is a idle.

 

I don't know if it's the angle of the photo or I need to calibrate the needle gauge. But as we speak it's showing 12.4V on Autoenginuity and 12.5V on the multimeter (with all accessories on)

 

That's honestly what I was about to say. The rear blower running on high sucks alot of juice and is what pulls the voltage down.

This is why I only put the rear blower one notch above "high". It still keeps the truck nice and cool, but my alternator is able to maintain 13.9-14.3 volts. (even with all the lights on: headlights and fogs)

I've found that the achilles heel of some of the parts store altrernators is the regulator. (hit or miss) The set point for most of them is 13.5 volts max. (I know, I've been through 3 of them in 6 months ) If they even try to go above that: "Hey! What do you think you're doing?!? Get back to 13.5!!!!". This was the case with the Autozone alternators I had and now have on the '05 Excursion.

I got tired of having crappy voltage that hardly kept things within spec and my FICM was starting to suffer, so I took it to a rebuilder, they took it apart, tested everything, and replaced the regulator with one that had a 14.5 volt set point. $55 later, Once the batteries are charged after the glow plugs being on, I get anywhere between 13.8-14.3 volts with lights and AC on idling.

With regard to the 6.0 alternator, it's a good upgrade. For several reasons:

-Large case vs. the stock 7.3 small case.
-110 amps vs 140 amps (might not seem like much, but it makes a difference)

As others have mentioned, it's just a matter of 3 bolts, and rotating the housing. If you have correct upper radiator hose, you'll need to cut a rubber hose to prevent the alternator housing from wearing a hole.

I really wanted a DC power alternator, but didn't want to give up a truck AND insurance payment to have the one I needed. I've upgraded the cables on both my trucks to 2/0, so the alternator is better able to keep the batteries charged; but if I had to put one on my wish list, it would be a 200 amp alternator since I don't want to have to wire up an external rectifier.

I need to go get the 7.3 from my buddy who was having his 6.0 bulletproofed, so I'll see what the voltage drop is on it. However, I hope the analysis I provided based on my experience with the 6.0 helps.

 

You loose .5 volts threw the port to. If you check it at the battery it shows more.