I am upgrading a dual alternator from a 2000 F350 Superduty 7.3L Powerstroke Diesel, Dually 2wd model. The factory alternators for this truck are 2 - 110 amp alternators. This truck also has two batteries, one main and one auxilliary. With the -40 below wind chill and subzero temps. from last years winter season in 2013 (Ohio) both factory alternators went down on me leaving me stranded. This truck has never let me down before and i have never been stranded like I was at this time, ever with this make, and model of truck. I bought two new 160 amp. alternators (upgrading with more accessories inside and out) and cannot find a high output alternator wiring kit to fit my needs with this truck. I know that i need 4 gauge wire approx. 6 feet from one alternator to one battery but, do i actually need 2 wiring kits? ( one for each battery with two inline fuses or circuit breakers) I have contacted several parts stores, individually owned parts stores, shops and talked with product personnel that sell wiring kits but, after many weeks still no luck on talking to someone who has actually installed an upgraded wiring kit to a F350 Powerstroke 7.3L diesel Truck. As a matter of fact, they end up laughing at the end of our conversation because they have actually never heard of or wouldn't know how to attempt the installation of a high output alternator upgrade! This is there own words. I searched the web, and came up with a diagram from Painless Performance for up to the 190 amp. install and it is only for a single component install. If anyone could help me figure this out or would have a complete diagram of correct install for a dual 160 amp. and dual battery hookup please help! I'd like to get this truck back on the road sometime soon. I know there are Ford Powerstroke owners out there that have had the same issues with the junk factory alternators for these superduty trucks. I also know that other owners have upgraded there systems installing camper accessories and towing equip. etc... I want to hook this up without blowing out my electrical system. If there's anyone that has attempted this project please forward any useful information or diagrams with pictures, details of this install. Thank you for any and all responses to this post.

 

I think your assumption of one main battery and one auxilliary is faulty.
A diesel usually has two 12 volt batteries connected in parallel to support high current requirements from glow plug operation and starting load when the temp goes down. I would have to brush up on the addl requirements for wiring and function of dual 160 amp alternators. As you stated there are some heavy gauge wires required to handle the max output of 160 amps each. Do you really need that much electrical power ?
It is very unusual for two alternators to go down at once. Did you ever find the reason for that?

Something they don't seem to mention anywhere and that is the horsepower required to drive those alternators. We were able to load down a 90 amp alternator on a ruck with a Cummins 350 HP diesel engine at idle and STALL the engine. There are considerations to consider and more is not always better and it comes at a cost and it's not always $$$$.

 

@ hanky,
Thank you for your quick response. Let me inform you regarding a little history on the truck. My father bought this 2000 dually diesel Powerstroke F350 Superduty Truck brand new and it was manufactured from the Kentucky truck plant in Louisville, Ky. I bought the truck thru his estate so, that makes me the second owner of this truck. The truck has only 110,000 miles on it to date, as I have several other vehicles I use to run errands. The 7.3L Diesel Truck was used only for work, roofing, electrical and hauls to pick up building materials. While my late father owned the truck he put 30,000 miles on it and at that mileage it had a slight oil pan gasket leak, as most make and models of this year do. Father failed to take it back to dealer at this time for repair while under warranty. I change oil regularly and use Rotella 15w, 40. There was a recall on the cam-position sensor years ago and that was replaced. Since i owned the truck I have pulled the front-end brake components, plus rotors off 3x's due to poorly built factory calipers and/or the rotors themselves. I replaced the front and rear with new drilled and slotted rotors and upgraded the caliper system with SSBC quick change parts-(well worth the investment) and flushed and replaced with Dot 4 Synthetic brake fluid-well worth the investment as I haven't had a problem since changing the braking system out 2 yrs. now.
Whereas, I'd had continually gouging of the front rotors from buying brand brake lines, new calipers and brake pads from Autozone with complete brake line flush. These were replaced several times with only 6-9 months usage with plenty of brake pad left. I've replaced both batteries in 2009 as the "main" wasn't pulling the load required on start-up.
My Ford Manual does refer to the diesel 7.3L powerstroke superduty as having a "main" and "auxiliary" batteries. In August of 2013 I finally had gotten around to fixing the lock mechanisms for the door locks as they had not been working right since taking ownership of the truck @ 30,000 miles. I had ran across a quick and easy fix on this fordforum site for superduty trucks such as mine. I took out the actuators from both doors and repaired the resistors in both actuators by the aluminum foil wrap method, It worked! I wondered later could this have caused issues with too much draw on the electrical system somewhere now that they are fixed? i didn't think so as the resistors aren't continually on but, why did these resistors go bad to begin with, with only 30,000 miles? There were no kids in the vehicle continually pressing and holding them down either. In an answer to your question on what made the original 110 amp. alternators go down at the same time, im not actually sure at this point as when i removed them, i took and had them bench tested and readings for both alternators were bad, these alternators were the original components since the truck was purchased (14 yrs. old) Upon close inspection, after taking them apart, i did notice that both slip rings were pretty worn. I've read several posts on the fordforum site with problems with the factory 110 amps not putting out enough power for these superduty trucks. In fact, the several posts I've read these guys have went thru 2 to 4 alternators within a few yrs. I also, read up about the DC alternator setups that have resolved alot of Ford Superduty Truck owners. After reading up about upgrades on other sites I decided that maybe i should just upgrade to higher output alternators as in 2010 when the temps. once again dropped into the - degrees here in Ohio my factory starter just wasnt cranking fast enough for this superduty truck in the extreme cold weather. I purchased a higher Torque starter from Tennessee and had it shipped right to me and boy, did it crank without any problems when the cold weather set in. Im not upgrading to other accessories at this point and didn't run the truck on very long hauls in the past but would like to do some traveling/vacationing maybe pull a good size camper within a year or two. Always projects to do and things to fix, needing a relaxing vacation that i never get to plan...any input is appreciated, thanx again!

 

Sounds like you have everything under good control. Those7.3s have a good reputation and will provide good service when maintained. Have you considered using a full synthetic motor oil ? Anything you can do to reduce the drag on cold starting usually helps. If you haven"t checked out the individual glow plugs , now would be a good time to confirm they all are good. It helps a lot when they all are working and does contribute to easier starting in cold weather. Do you plug in the engine heater when you can ? That 7.3 will really deliver when it has to ! Keep an eye on that oil pan , they are known for rusting out and developing leaks.