Does anyone run dual atls does ford have a factory part for this or would it be all custom brackets. What I want to do is leave the factory alt and battery just for the truck. then put a second alt with 2 batteries for lights, winch, stereo, cb, this would be in a 99 250 4x4 v-10

 

ford has a dual alt option but its only for the diesel...i think your best bet is to install a high amp alt...ford now offers high output alts (200 amps)on the new fseries and the aftermarket make some huge one too...adding a second battery would probably be enough and a lot easier than adding a third

 

I have seen the high output alts I was thinking of going with dual 200amp alts. Just a little over kill but i would like to have it there if needed. You can never have to much power

 

i was at a truck convention and there was a vendor that made some insane alternators...i dont remember there name bc it was a couple years ago...around 300 amps if not more if i remember correctly...probably a lot less of a headache swapping alternators than making brackets, harnesses, clearance issues, etc

 

At that many amps you'll need new battery cables. Probably 4ga would do it.

 

I ran them with my diesel. Like the others said I would just opt for a higher amp alt.

 

under the hood of alot of limos they have dual alternators. the second one is backwards facing with special brackets and a longer serpentine belt. (alt case to the front and pulley facing rearward). not sure how its wired, but ive seen a few.

 

I was going to use 1/0 fine stranded welding cable for the wire on the battery and the alt.

 

For anyone was looking to add a second alt also I have found two web sites with help from people on this site I just want to past it on.

www.davesdcelectric.com
Limousine parts and accessories - Modern Technologies Group, Inc

 

That should do it if you can get it run correctly.
Those look like some nice alts. Looking on their EBay store I can't figure out why the one priced $229 is cheaper then the one for $298. Seems like the price is backwards after reading the specs.

 

Nice!
For the record, if you just increase the size of the wiring on the stock alternator and keep the wire as short as possible you will get more output. The stock wiring is sized as a compromise between resistance, packaging size, weight, and cost. Since the average user very, very rarely needs full output and then, only for a few seconds at most, the wiring can be much smaller than what would be optimal at continuous peak output. And the stock wiring run is never a straight shot.
Smaller gage and longer run means more resistance in the wire, reducing voltage transfered and current output.
If you demand high output for extended periods, the resistance means the wire heats up. Heat means even more resistance.

Here's a neat little ampacity calculator.
AWG

As you can see, the 8 AWG commonly used is less than ideal at continuous high output.
I typically add a couple runs of 4 AWG to my vehicles when I add big stereos, extra lights, etc. I leave the stock wire, just add more. 4 AWG welding cable is easier to run and terminate. And pretty cost effective.

Don't forget to upgrade the ground path as well!

Keep in mind that more output from the alternator means it will get hotter as well.... This is quite hard on the regulator and rectifier and they will fail much sooner than if exposed to normal use. If you will be using high draw electronics a lot, You may need to consider a heavy duty rectifier, something like this:
Dual/ Remote Rectifier Alternator System, Dual output Alternators