# Alternator Upgrade from 110amp to 200amp...Am I missing anything?



## coldcoffee (Jul 17, 2008)

This truck is an 03, F350 6.0 Powerstroke Diesel.

Since I can't seem to get more than 2 years out of any brand of stock sized alternator's on this truck, I decided to do an upgrade from the 110 amp to 200 amp alternator & replacing my 3.5 yr old yellow top batteries w/ 875 cca Napa starting batteries. Done w/ the yellow tops.

Got the alternator delivered Fedex today & just ordered a Napa harness to do the upgrade. Below are the parts, but just want some opinions as to weather I'm overlooking anything.

Parts list:

Video of the unit that I just purchased:






Link to the cable kit (from Napa):

http://www.napaonline.com/Catalog/C...-Electrical-Connector/_/R-RAL1331K_0338205387

If the link doesn't work, the Napa part # is 1331k

I have a good relationship w/ my Napa parts guy, but he wasn't sure about this wiring kit, nor was I. Decided to order it anyway, so we can at least check it out together. If I don't like it, I'll send it back. It's what Napa recommends for doing this upgrade.

My question though...Am I missing anything?.... Additional grounds, larger serpentine belt to compensate for the larger housing, which I believe adds about 1/2" of height, or is there anything else that I'm overlooking such the Isolator.


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## linckeil (Sep 18, 2007)

the napa link doesn't state it (or i didnt see it), but what gauge are those cables? you definitely want 2 gauge. and what is the rating of the inline fuse? you want 15-25 amps higher than your alternator's maximum output. so with a 200 amp alternator you'd want a 225 amp fuse (they may not make that size, in which case you'd go with a 250).

this is the guy for ford alternator upgrades (at least for the pre 2000 cars/trucks). his prices are the best and he individually tests the output of each alternator as many off the shelf models don't put out nearly the power they advertise. it may be too late since you already ordered your parts, but its a worth an email to this guy, even if he may not list an alternator for your particular application. but i gotta imagine his wiring kit in the link below is of better quality and less cost than what napa is selling....

http://www.rjminjectiontech.com/col...essories/products/alternator-charge-cable-kit


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## coldcoffee (Jul 17, 2008)

I agree that the cable description is rather vague, as I couldn't find that info either. The only thing we had to go by was after he looked up a Napa 200 amp alt., the description made reference to that harness & said it was required. I wasn't even aware that Napa had the large case 200 amp unit...which I had already ordered from the other guy. The unit that I ended up purchasing, I actually bought from Ebay...which was less money than buying directly from his website. He lists them there also.

I had a good 20 minute phone call with him the other day and felt pretty good about going ahead w/ the purchase. My problem now is mixed information and information overload from too many sources, to what should seem like a relatively simple project. 

There is a lot of mixed info about cable size, how many, to where, fuse link, no fuse link needed, does it have a battery isolator, if so...is the isolator large enough, is it even an issue, and was even told from another battery guy that I needed to upgrade the starter cable...but not the cables between the batteries. My head hurts.

thanks for that link, I'm going to tool around w/ that a bit. Tomorrow morning we look to see what this Napa kit is all about, when it comes in. My Napa guy is as curious as I am. Was hoping someone was maybe familiar w/ it.

I know Napa isn't cheap but today I felt obligated to at least buy the batteries from them, since I'm always getting free advise. Been doing that for over 25 years w/ these guys. But if I find a better, more cost effective, comprehensive and thorough option...I'll probably go that route instead.


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## dieselss (Jan 3, 2008)

No need to ungrade the starter wire or you already have a dual batt set up


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## coldcoffee (Jul 17, 2008)

Thanks guys. Linckeil, I did check that site out. It's seems as though he doesn't do 200+ amp units & offers his reasons as to why he doesn't...belt size, groves & belt slippage, etc. Perhaps it has something do w/ all these younger guys trying to put them in their small compact cars for their stereo systems.

I did find these guys (link below) while searching on The Diesel Garage. They apparently also build units and cables to order. I sent them my question, if the answer is good I'll try and post it.

I know there is a lot of discussion around about this, but 90% right doesn't guarantee no heat or melting issues & gross overkill is just wasting money.

https://www.dcpowerinc.com/universa...er-charge-cable-kit.html#tab-product_overview


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## Antlerart06 (Feb 28, 2011)

linckeil;1668638 said:


> the napa link doesn't state it (or i didnt see it), but what gauge are those cables? you definitely want 2 gauge. and what is the rating of the inline fuse? you want 15-25 amps higher than your alternator's maximum output.  so with a 200 amp alternator you'd want a 225 amp fuse (they may not make that size, in which case you'd go with a 250).
> 
> this is the guy for ford alternator upgrades (at least for the pre 2000 cars/trucks). his prices are the best and he individually tests the output of each alternator as many off the shelf models don't put out nearly the power they advertise. it may be too late since you already ordered your parts, but its a worth an email to this guy, even if he may not list an alternator for your particular application. but i gotta imagine his wiring kit in the link below is of better quality and less cost than what napa is selling....
> 
> http://www.rjminjectiontech.com/col...essories/products/alternator-charge-cable-kit


I wouldn't buy NAPA Alternator I went thru 3 of them all said was 135 amp last one I took to a alternator shop only put out 88 amps at 2k rpms and would put out 135 at 6k rpms I bought this 2days ago and My plow was pulling lights down. That's reason I took it to get check out today. I bought one from O Riley's and stop at the alternator shop and it check out to be true 135amps at 2k rpms. Plow doesn't dim the lights now

The alternator shop told me watch out on NAPA stuff is miss printed or put in the wrong box

Reason I didn't buy one from alternator guy. He said his warranty was a year O Riley's was a Lifetime.


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## coldcoffee (Jul 17, 2008)

After replacing several Napa alternators & starters on different trucks and never being able to find my receipt for a claim, I started getting them from Advanced Auto w/ the lifetime warranty, because they actually have you in their system.

What I don't like is when a starter is working intermittently, they test it and say it's good. My last alternator replacement with them I had to go round and round until I lost my cool. They kept asking me if this was on a plow vehicle and I wouldn't tell them. I finally got my second replacement within 2.5 years, but what a headache. The guy kept crying about how his regional manager was tightening up on claims...I said put him on the phone.


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## linckeil (Sep 18, 2007)

did that kit ever come in from napa? i'm curious on the wire gauge and fuse size. really strange they wouldn't state these 2 key specifics on their website.


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## coldcoffee (Jul 17, 2008)

I picked up the kit Saturday, but haven't done anything yet other than install the new batteries. Went straight to plowing and salting since I put them in. Thought I'd have a break tomorrow, but another 18 hours of lake effect on it's way starting now.

Anyway, it's 4 gauge wire w/ a 200 amp fuse. My Napa guy insisted that I'd be fine w/ it, stating it wouldn't be an issue w/ what I'm running, and unless I had really long runs causing a lot of voltage drop. He agreed that I should add a few grounds. I looked at a chart and it seems to be within range. But then I got this response from DC Power Inc. :

*Your passenger is your main battery which means that you pull power from there first, if necessary then the secondary will trickle into the first battery through the 1/0 awg that's in between those two batteries. Which means you don't have to touch that secondary battery at all, the cable is big enough to support the flowing current. One kit is sufficient enough for the main battery, it will help with current and lower resistance in the system which means less voltage drop.

This is how I would go about that setup:

Positive from charge stud to ANL Fuse.
Positive from ANL Fuse to positive on battery.
Negative from negative on battery to alternator mount.

Also a isolator is not required and there are plenty of people that don't run them.

Let me know if you have any questions!*

Here's the chart:


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## dieselss (Jan 3, 2008)

I like the chart. I still would have gone with 2g. Just my .02


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## linckeil (Sep 18, 2007)

yeah, like I said initially, 2 gauge is what I would go with. 1/0 is overkill. 4 gauge will likely be fine, but i'd have much greater piece of mind using 2 gauge with a 200 amp alternator. 

the 200 amp fuse should be ok also. they are slow burn fuses, meaning they can handle their rated capacity (and even higher) for an extended period of time. not likely your alternator will need to put out 200 amps for more than a few seconds here or there under extreme load conditions. nonetheless, i'd buy a 225 or 250 amp fuse and keep it in the glove box just in case.


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## coldcoffee (Jul 17, 2008)

I totally appreciate what you guys are saying but remember, I'm not starting from scratch, I'm only adding to the existing system. If a 4 gauge harness is within the limits, then shouldn't 2 - 4 gauge wires put the insurance on that is needed without going overkill?

I can see going one size up on the fuze, which I'll do...Have to order it though, my Napa only stocks up to 200 amp.

I see so much bad or misguided info out there where one just mimics the next. The mass of info seems to be mostly built around young guys building their stereo systems w/ 0/0 gauge and what not, sometimes w/ no fuse link...just down right scary. I've experienced melt downs, fires and even had a battery blow up in my face once when helping a guy w/ a jump who crossed the cables on my hot battery from plowing all night. That's why I want to know the math first.


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