Couple drops of LocTite....fix that right up.

 

@Y2KW57 Did you mean the fuse on my aftermarket battery cables?

I have circled the fuse in both pictures.

 

I learned this lesson the hard way many years ago when I took a 3.8L supercharged car and mucked it up so badly with "upgrades and performance" parts that it was a pain in the *** to keep running right and not break anything. A friend of mine that had the same car with similar "upgrades" cracked a couple of pistons. I was luckier than that I guess and sold the car with full disclosure of the issues it now had.

I swore to never go down that road again and fortunately I have stuck to that since those dark days. I bought a 2004 4.2L V8 Audi S4 with a 6 speed manual which needed no modifications to be fast and comfortable. I a couple of sport bike motorcycles to satisfy my "need for speed" including a 1340cc Hayabusa that I ran over 175 MPH when I stopped checking the speedometer.

My point is, some vehicles were designed for specific purposes and when you push their design purpose too far you now have an unreliable and troublesome vehicle.

Regarding my 2000 7.3L. We purchased it to be a tow pig for our 5th wheel and property maintenance aid. This is why I have only done modest "modifications" to the 7.3L as it sits. 6637 Donaldson filter, Hydra with 65 HP tune, 160A alternator, Borg Warner SXE turbo, OUO traction bars and an Android head unit. Most everything else is OEM specification or OEM from the factory floor and still chugging along at 267,000 miles. Even though everything is mostly OEM, the truck still tows the 5th wheel at 18,000 lbs GCVW or more cross country and up to 9,000 ft elevation just fine.

We have to realize the limitations of the engineering and design when replacing or "upgrading" parts. Things like the Denso starter I installed on the truck do not fall into that category in my opinion as they are not in the working category, they are auxiliary equipment. Speaking of Denso, our 2008 Subaru that has 150,000 miles on it has a Denso sticker or part number on a lot of the parts under the hood. That vehicle has been rock solid (knock on wood) for many, many trips cross country and 4x4'ing in the mountains of MT and ID. The reliability of Denso that we have experienced first hand is just one reason why I pay more for quality parts like the Denso starter in the truck.

Exceeding the design and engineering of a vehicle or product is not only a fault of our own, but a fault of some of the aftermarket companies that we send our money to. I have done it and will do it again I imagine.

INFRNL, I hope Mechman can make it right by you and I am sure you are a bit wiser now by learning something the hard way. I thank you for sharing your experience with us though so that others may learn from your experiences instead of having to go through them in their own time.

This is a picture of my fuse block, which I took directly from Y2KW57 and his method of fusing the LN alternator.

 

I will get some of those MRBF blocks and fuses. Thanks

 

No, I didn't. (But thank you very much @FordTruckNoob for your response, and for your photos).

What I actually meant was for you to post the alternator to battery wiring diagram out of the FSM for a 2002-2003, since that wiring is a little different from the 1999-2001.

The reason why I wanted you to post the wiring diagram is because @INFRNL had said...

I wanted to you to prove to INFRNL that the factory B+ cable is fused, and I knew you had the facility to do so, along with the street cred on FTE to be believable to boot.

In fact, I don't know anyone on FTE who is more riveting.

Here's the diagram...




Shown and blown below are the OEM fusible links on the lead from the alternator to the curbside (passenger side) battery of a 2002 F-250 7.3L diesel belonging to dgiles, of TDS, to assist you in confirming location.

 

@Y2KW57 Oops, my bad. Sorry.

 

I'm not sure how I missed that bottom pic...I'm going to have a look at mine...I'm not doubting anything just curious.

@FordTruckNoob way to go dropped the ball and made the boss do your job

 

If I'm looking at this correctly, you have the OEM alt cable hooked up where the MRBF connects to the B+ alt stud? then you added another cable hooked to a MRBF fuse, then have a spare connection?


Also, in regards to @Y2KW57 post showing OEM fusible link at the battery....typically you want the fuse closest to the source. I'm guessing in this case it doesn't matter because the battery is also a source? so if adding an alt cable or replacing with larger gauge cable, you could put an inline fuse on the battery side rather than using the MRBF (but you could also use an MRBF instead of an inline like Johns)

I'll need to draw this out because I think the B+ between batteries should also be fused. So it would make more sense to do a dual MRBF at the battery or could use singles but that would be more expensive for the same task. I do like it at the Alt though for a nice clean look.






I just reread this...I believe even if my added alt cable was fused, the events would not be any different and it wouldn't have blown a fuse. For example, you have an amplifier that has a fused power source and even internally fused. If a capacitor, coil or something fails, it will not blow the fuse... only the component fails. If the Failed component causes a short in the main power path, then it would blow a fuse. I think I said that last part correctly

 

To add a fuse on the batt cable that connects the two battery positives together, wouldn't you technically need a fuse at each end? One at each battery? If you put it to one side it won't stop the opposite side from being shorted to ground if an accident were to happen. So you would have to put a fuse at both batteries?

I've got a few anl fuse blocks handy as I use them alot, I should put one on my alternator feed as I currently don't have one. I guess I should also put two of them at each end of the cable connecting the batteries together.

I have one of those fuse blocks at the driver side battery where my feed to charging my dump trailer goes from driver battery to the flush mount plug in the bed of the truck. One of the other ones is for my power cable for my multiple amps for my sound setup. The last one I have currently is feeding my new fuse box I installed. Sounds like a need a few more now though!

 

You missed the photo because I snuck it in after the fact. I couldn't find a good one quickly enough on FTE, so I pulled one over from another forum.

Wire diagrams are great to know how the circuit was designed, but photos of where stuff like fusible links are actually located are even more helpful.

The fusible links on my truck are in a different location than on your truck, so I either had to find someone else, or someone else's photo, to show you.



Yes, you are looking at that correctly.

Here is the original example of my method of fusing the LN alternator that Sous patterned his installation after.

I had two reasons for using the double post MRBF. The first reason is simple enough: I added two additional charge wires, one to each battery.



The second reason is that I wanted the MRBF sled to be long enough to clock against the protrusion of the slip ring end bearing cover on the back of the case, which would quite conveniently serve as an anti-rotation stop, since large battery cables are heavy, and might have a tendency to vibrate out of position without a hard stop.



The point of view in the photo below is as if you were a mouse living in the air cleaner box, peering out of the engine side inlet without the snorkel, looking at the back of the alternator from the firewall side of the engine bay, sizing up some tasty wires to gnaw on overnight...



A very important, yet very hidden aspect of this wiring installation are closely matched diameters between post and wire lugs.

The inside diameter of the wire lugs were specifically chosen, and where necessary, modified, to have an interference fit with the outside diameter of the wire posts.

At no time was there an 11 mm lug hole fitted over a 10 mm stud (as a hypothetical example). The diameters between stud and hole were matched as precisely as possible, because that literally is where the magic happens. The connection is where the circuit makes or breaks contact. And regardless of how thick the wire cable is, all that aught is for naught if the surface area of the connections are minimized from mismatched diameters.


Yes, you are again correct.

MRBFs were designed to be mounted at the battery. I was the first person that I am aware of to flip that script and mount them at the alternator instead, primarily because I did not want to stack battery cables on the B+ post, and I had three to stack... the OEM cable serving the glow plugs, intake air heater, and starter relay, and my two direct charging cables, one to each battery.

Stacking cables on a horizontally oriented post, where the attached cables would swing with the way the engine rolls on every acceleration event didn't seem like a good idea. If one looks carefully at the OEM alternator B+ post shield on the back of a 6G, it will be observed that there is both an anti rotation and an anti cable swing provision incorporated into the shape of the insulator. Ford knew. Yet the 6G insulator could not be used with the Leece-Neville, which had a larger diameter B+ post, and electrical contact surface area surrounding the base of that post that needed to be taken advantage of with any cable attached thereto.

Mounting more cables to the battery is easy. But mounting more cables to the alternator was a challenge. I kept thinking about how I could surmount that challenge with a buss bar of some type, that would give each B+ cable connection a separate post, such that the applied torque from the nut holding the cable in place only had to counter act the swinging weight of one cable. And that is when the idea came to me. Make that bus bar the fuse bar at the same time. The same device can solve two problems... the need for the cable to be fused, and the need for the cable to be mounted.


Yes. MRBFs were designed to be mounted at the battery. Hence the name Marine Rated Battery Fuse.

No OEM that I am aware of fuses cables that run directly between batteries. This is true whether the batteries are paralleled, like ours, or wired in series, like 6 volt house batteries in a motorhome. This is true on Peterbilts, with 3 or 4 group 31 SLI batteries in the box, and Priuses, with dozens of batteries in the hybrid pack.

I wouldn't worry about fusing the paralleling cable that crosses the radiator from battery to battery. If you are concerned about dead shorts in a collision, then you can add more insulation protection to the cable.





Instead of one paralleling cable between batteries, I have two. This was a thriftier method of reducing resistance between paralleled batteries, and equalize the load and charge between them. The thrifty aspect of it was reusing the OEM cable, and just adding another, instead of changing out the OEM cable for a larger one.

But I did temporarily remove the OEM cable, to triple wrap it with anti abrasion coverings (spiral loom, split convoluted loom, and a lot of red tape).




Either way. Whatever suits you. Just as long as you have a properly rated fusing device between the battery and the alternator of some type, rather than none at all.

The design was driven by the desire to mount multiple cables to an alternator with only one B+ post.

You could certainly mount your fuses at the battery, or use fusible links at the battery, like Ford.

Just so long as the cable between alternator B+ post and the rest of the vehicle, including the battery, is fused.

 

I have the OEM B+ connection on a post instead of mounted directly to the B+ stud. I then have additional cabling from the B+ to the batteries.

I have a thread on the modification and have linked it here: My truck needed to be more POSITIVE and ENERGIZED!

Again, 90% of the design credit goes to Y2KW57. I prefer to learn from the experiences and trials of others instead of going through them myself. I hope this helps.

 

I don't have time at this moment to read all of these new posts as in depth as I'd like as I'm waiting to go into the court house, but I was thinking of getting something like this and mounting it near my driver side battery. I would have the alternator feed one, my charge cables going to the back of the truck on one, the cable I'm gonna put for a front mounted winch on one, and the cable for connecting the two batteries together on 1. Definitely not cheap but a awesome piece nonetheless. I would probably make a plate to connect the battery side of the fuses all together so only one big cable would be necessary to connect all 4 to the battery.

​​​​​​https://a.co/d/eKi3cVH

 

I must admit my reverse-delegation skills are pretty impressive.

 

Thank you...I will reply back on your response when I have more time. I appreciate your time and knowledge
Thank you as well, I'm always looking to improve
Sorry for somehow hijacking your thread...Oh I remember how it started
At least the responses will help everyone

If you had a 3D printer, you could make your own. There should already be versions like that, that have a buss bar on one side for a 1 in 4 out setup...none of them are probably on the cheaper side though.

Maybe you need something like this Blue Sea 5196 it's a surface mount MRBF takes up less space

They are indeed

 

No need to apologize or stop lol I am enjoying everything everyone is talking about!

​​​​​​That would be a perfect fuse block if it had 4 circuits instead of 3!