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Those with Dual Alternators

58K views 64 replies 20 participants last post by  clev 
#1 ·
Could someone with dual alts let me know where the secondary alt output goes? Does it go to the secondary (PS) battery? Also, where does the harness to the field connector plug in? I can't find any unused plugs within reach of the harness.

Any help would be appreciated (photos especially!)
 
#2 ·
Do you have them already or thinking about adding them? Some years ago, I believe on this forum, there was a discussion about how Ford programmed the duals to alternate useage, unless draw was high enough to need both. I seem to remember it was very complicated how the computer used them. I had them on an '04 but never did any work/diagnosis on them.
Joe
 
#3 ·
I have them installed - but not yet enabled. I have to visit the dealer Monday morning. I did find where everything plugs in - it's detailed in the 2011 Wiring diagrams book.

FYI - while I was checking the wiring, I discovered that on startup, the truck draws approx 80A for the engine/electronics and the cab heater draws an additional 80A for a total of 160A!!! That 200A HD alternator is already maxed!!! I'm sure it's not rated for much above 160A at idle.
 
#8 ·
FYI - while I was checking the wiring, I discovered that on startup, the truck draws approx 80A for the engine/electronics and the cab heater draws an additional 80A for a total of 160A!!! That 200A HD alternator is already maxed!!! I'm sure it's not rated for much above 160A at idle.
I'm assuming that's without the navigation system as well? Did you have your headlights on at the time?

I'm imagining the extra load those things (plus heated seats, etc if it's cold) could place on the truck. Even worse if you have a trailer hooked up and let it idle to warm up a little before driving, as I always do when cold as well. I hadn't really considered dual alts on the new one we're looking at, but I think I'm going to now.
 
#4 ·
Is that what everything is rated at or what it draws? Anyone put an ammeter on it to check the draw at startup with the in cab heater?

But.. I can see how dual alts for the in cab heater would give you peace of mind over the one HD alternator for that application.
 
#5 · (Edited)
That is measured with an ammeter - right on the primary (200A) alternator output line, right when the truck was started, with the cab supp heater running. The draw on the truck eventually drops down to approx 58A (when warmed up) and the supplemental heater lowers it's current as the truck's coolant warms up, but the 160A is real.

You can see indiviually what each device draws by measuring the separate current at the high-current battery junction box (that's where the cab heater is fed from - off a 125A mega fuse)

The reason I did the dual alts was to run my winch (10, 000 lbs) - that can draw some serious juice - even ignoring the cab heater draw.

I'd be very interested in finding out what the 200A alternator output is rated for at IDLE. My guess is somewhere right around 160-170A.
 
#7 · (Edited)
Dual Alternator Wiring Install

Hi All - I am new to this forum and a new owner of a 2012 6.7 F350. I am wanting to install the second alternator on my truck. I have purchased all the parts listed in the Ford Q-161R1 bulletin. However I can't find where the electrical harness and battery wire hook up to. I see the OP found this in the wiring diagrams, however I do not have access to these and don't want to pay the stealership to hook the wiring up. I apologize for posting on a year old thread but there is very limited info for this install on the web. Does anybody have this information?

Thanks - Craig :ford:

2012 F350 SRW CC Short Bed Lariat FX4
 
#9 ·
Craig,

You can PM me and I can send you the diagram. It was REAL simple once you see the drawing. The pain in the neck is having to take it to the dealer to get it enabled. My truck was the FIRST dual-alt that was NOT done at the factory, so it took the dealer over a month to get working software to enable the second alternator... what a PITA...

rforsythe,

All the lights were on, but I don't have heated seats or the navigation system. With the second alt, the electric cab heater works faster than stock. My brother-in-law has an 2011 F-350 with the single HD alt and is not happy with how fast the electric cab heater heats up (after sitting in mine)
 
#13 ·
I don't know . My 2006 F-350 came with the set-up ( I just got lucky ) , but I ordered my 2008 F-450 with it installed from the factory . I would be careful about installing a second alternator , even though the block comes drilled for the two alternator set-up , FORD MOTOR COROPORATION IS GETTING PRETTY CS ABOUT ANYTHING YOU ADD TO THE TRUCK AFTER IT LEAVES THE LOT , IT WILL VOID YOUR WARRANTY IF YOU ADD IT AND TIE IT INTO YOUR ELECTRICAL SYSTEM:headbang::headbang::headbang: W5DVC911
 
#14 ·
W5DVC911 - I am about to do this upgrade to my 2012. Do you have any information or a doc from Ford that says this upgrade will void your warranty? I have the FORD Service Letter Q-160R1 and it has no info about a second alt. having to be installed by a Ford Dealer. My F350 only has 6000 miles and I would hate to void the warranty or extended warranty. Thanks





2012 F350 SRW CC Short Bed Lariat FX4
 
#16 ·
According to the shop foreman @ KINSEL FORD anything you add to the truck after you receive it voids the warranty .You should probably talk directly with a FORD MOTOR COMPANY REPRESENTATIVE AND WORK WITH HIM TO RESOLVE THIS ISSUE .:yesnod:
 
#15 ·
06redzo6 - I have about $552.68 in parts to add the second alternator. Not sure how much the dealer is going to charge to set it up in the PCM. The bad thing is you have to change out the secondary cooling system water pump. The alternator mounts to it.
 
#18 · (Edited)
Magnuson–Moss Warranty Act.
 
#19 ·
^^ +1. The most a dealer can really tell you is that modifications MAY void the warranty, if what you did caused a failure of the warranted part. It certainly isn't going to void the whole thing (i.e. if you add a part that breaks a sensor, that doesn't automatically void say the wheel hubs too for example). That law exists specifically to protect consumers from BS claim denials based on modifications that had nothing to do with the component failure.

In the case of dual alternators (this thread), if you're adding Ford parts and having a Ford shop reprogram the ECU to control them, they will be on shaky ground trying to deny you for anything related to that. If you're really concerned about it then have Ford install the stuff too -- then it's really all on them. If you wire in the alternator poorly and it shorts out, blows up a bunch of expensive electronics, etc then yeah, that is on you. But one would have to lead to the other.
 
#20 ·
^^ +1. The most a dealer can really tell you is that modifications MAY void the warranty, if what you did caused a failure of the warranted part. It certainly isn't going to void the whole thing (i.e. if you add a part that breaks a sensor, that doesn't automatically void say the wheel hubs too for example). That law exists specifically to protect consumers from BS claim denials based on modifications that had nothing to do with the component failure.

In the case of dual alternators (this thread), if you're adding Ford parts and having a Ford shop reprogram the ECU to control them, they will be on shaky ground trying to deny you for anything related to that. If you're really concerned about it then have Ford install the stuff too -- then it's really all on them. If you wire in the alternator poorly and it shorts out, blows up a bunch of expensive electronics, etc then yeah, that is on you. But one would have to lead to the other.
MAGNUSSON-MOSS WARRANTY ACT .................THANKS FOR THE INFO , NOW THAT IS USEFUL INFORMATION .......THANKS AGAIN W5DVC911
 
#21 ·
Thanks for all the information. I went to my local Ford dealer and talked to the service manager. He pretty much said what rforsythe said. If they install the parts they are only covered under the standard 12 month/12,000 mile warranty. I will install the parts myself as ford wants over $600 in labor to install them. Just to have them enable the second alternator in the PCM is one hour of diagonistic fee or $111.50. I was able to talk to a tech and he told me it takes all of 5 minutes to turn it on in the PCM. Whats a guy to do? I sould have ordered it with duals from the factory I guess.
 
#23 ·
I'm half way through my 3rd winter with this truck. I remote start it frequently and I know the rapid heat is on during those remote starts. Often in the morning, it also has the marker lights on, since they come on automatically with the remote start. And I just haven't had a problem.

If I knew I was going to be using a winch, I'd just make sure the truck was warmed up past 100° on the coolant so the Rapid Heat shut off, before I ran the winch. You are talking 5 minutes at idle and even less time if you are driving before the Rapid Heat turns itself off. If you review the operation of the Rapid Heat you will see it turns on automatically if the coolant is less than 80° and turns off once the coolant passes 100°. So it is never on very long. And if you have had the truck running, it won't be a draw at all.

The single alternator is pretty simple to change out when they fail. Two bolts, all on top of the engine. The hardest part is changing out the belt. My experience has been the alternator dying around 100,000 miles, So it's a given to change the belt at the same time.

The second alternator, if it fails is a bugger to get to, as evident by Fords charging $600 labor to install one. I seriously considered ordering the dual when I ordered mine, But decided I'd gamble on getting enough voltage from one.
 
#24 ·
I tell all of my customers to get it. Plus it is a added safty bonus if one goes bad plus its driven by another belt.. I had a customer fry a belt and if it was not full the extras alternator he would have not made it to shere he was going.
 
#27 · (Edited)
I assume this was a 6.0L? (Which has different belts for each alternator)

I usually replace the belt after only 15,000 miles and keep the belt I take off ( I put in the same package the new one came in and stick it in my tool box)

15,000 miles really? Whew... I feel bad if you were doing that on your 2006. But really, 15,000 seems a bit excessive. What is Ford's recommended service interval for the serp belt?
 
#25 ·
Actually the second alternator is driven by the same belt that drives the primary alternator and everything else on the front of the engine. There is only one belt on the 6.7 powerstroke. I just did this mod to my truck. The only differance is the dual alternator belt is longer.
 
#26 ·
2ND ALTERNATOR

That is correct , both alternators and the rest of your equipment is driven by 1 belt . As a safety factor because I spend so much time off-pavement , I usually replace the belt after only 15,000 miles and keep the belt I take off ( I put in the same package the new one came in and stick it in my tool box ) just in case I loose a belt .............AIN'T NO AUTO CLUB OR TOW TRUCKS IN THE JICARRILLO (APACHE INDIAN RESERVATION) OR OUT IN THE LOW OR HIGH DESERT .:thumbsup:W5DVC911
 
#28 ·
Hmmm I still have the factory installed belt on my truck, 300,000+ miles and over 16-1/2 years, no cracks in the drive ribs, no fraying on the edges, I check it frequently. Yes, the spare I bought "just in case" is now about 10-12 yrs old and still behind the seat with the new tensioner & idler and all the tools to install them all.

I could see carrying TWO spare belts but it sounds like W5DVC911 would have TWENTY by the time he gets to 300K! ;-)

I still have a PSD brochure from when I was shopping for my truck that says IH/FMC tested the serpetine belt for 100,000 miles minimum life expectancy on the OBS trucks.
 
#31 ·
they must have changed it from the 6.0...

I was not aways that they went to a single belt now. I guess I learned something today :)
 
#35 ·
I know this thread is a month old but I felt that I need to add my experience to the thread because I haven't heard anyone mention doing it the way I did it and it might help a future forum member in regards to considering all options when wanting more amps out of his alternator.

Instead of going with a dual alt configuration And after a lot of research I called the guys over at mechman alternators and bought there heavy duty 370 amp alternator. It was actually bench tested at 390 amps max all with just a simple swap out of my stock single alternator on my 6.7. Not saying its the best way to do but It but I'm getting more amperage than with guys with a dual alt set up. And if I ever wanted more I still have the option to add that second alt.
 
#36 ·
I know this thread is a month old but I felt that I need to add my experience to the thread because I haven't heard anyone mention doing it the way I did it and it might help a future forum member in regards to considering all options when wanting more amps out of his alternator.

Instead of going with a dual alt configuration And after a lot of research I called the guys over at mechman alternators and bought there heavy duty 370 amp alternator. It was actually bench tested at 390 amps max all with just a simple swap out of my stock single alternator on my 6.7. Not saying its the best way to do but It but I'm getting more amperage than with guys with a dual alt set up. And if I ever wanted more I still have the option to add that second alt.
We usually order dual alternator on our trucks because the dual's have ~250A of output at idle which in our experience is where the aftermarket high output alternators seem to struggle.

Looking at the Mechman site the 370A Elite alternator starts at $699 compared to the $380 MSRP (so ~$315 actual cost) for the dual alternator option from Ford which is factory installed and is covered by the factory warranty which for us makes the aftermarket option not a viable one.
 
#39 ·
Yes, I'm regenerating a 5 year old thread. With my new 5th wheel and six 6-volt batteries, I'm finding that the truck does a poor job of charging the RV batteries. Before my next trip in the spring, I'm going to replace all the incandescent lights on the truck with LED's and am doing research on either a dual alternator setup or one high amperage alternator. Does a dual setup cut into fuel economy? I'd appreciate any input that anyone could provide. One thing that concerns me with the duals is 'dealer programming'. With the work that I've done, I don't want a dealer programming anything on my truck. Is programming a must? I'd like to just install the extra one for charging trailer batteries. Run a 8 gauge wire from the output, through a circuit breaker, to the distribution panel for my batteries. Again, any input would be appreciated.
 
#40 ·
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