Builds Moonshine - A Build Thread (11 Viewers)

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I completely agree that I need chafing protection (and I had planned to install it), but I'm not convinced that fuses are necessary for the battery cables. I agree they won't hurt, but I certainly don't think I'm going to burn down the truck without them. Why isn't there a recommendation to fuse the main starter, or alternator cables, if they're capable of carrying the same current?

When I install a winch, I will absolutely fuse the winch cables.

I have immense respect for you @Cruiserdrew, so what is your logic with the need for fuses here?
 
GLTHFJ60 said:
I completely agree that I need chafing protection (and I had planned to install it), but I'm not convinced that fuses are necessary for the battery cables. I agree they won't hurt, but I certainly don't think I'm going to burn down the truck without them. Why isn't there a recommendation to fuse the main starter, or alternator cables, if they're capable of carrying the same current?

When I install a winch, I will absolutely fuse the winch cables.
Click to expand...


My truck has a fusible link between the battery and alternator etc....can't say all 60 series do but every one I've seen has it.
 
woytovich said:
I think I have been dissed! ;)
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That was not intentional my friend :D Thanks for the links.

theron said:
My truck has a fusible link between the battery and alternator etc....can't say all 60 series do but every one I've seen has it.
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Yes. From the factory you have the fusible link, which is good (and it's saved me once) but it's a common upgrade on the 60 (or at least it used to be) to run a large gauge cable from the alternator positive lug directly to the battery without a fusible link.

In addition, the main power cable from the starter to the battery does not have a fuse even in the factory configuration. The fusible link is an obvious location for a fuse because it protects the vehicle harness from the battery and alternator.

I guess the point I'm getting to is which cables do you fuse and why? I would say fuse the winch because it's outside of the engine bay to prevent some hooligan from permanently jumping lugs or prevent lugs from melting off (@jfz80 knows what I'm talking about) but I don't see a need for fuses for battery cables under the hood. Chafe protection, yes, absolutely, but not fuses.

Just trying to think it out thoroughly instead of throwing money at it!
 
No worries Johnny... just messing with you. :cheers:

As far as the need for a fuse on the wire across the front of the truck... it is much more vulnerable than the wire from the alternator to the battery or the battery to the starter... IMHO

And just because it wasn't fused from the factory... well we all know how we feel free to "upgrade" other things that are not how we like them from the factory... ;)
 
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Yeah I have no doubt that folks modified alternators and bypassed a fuse along the way :) but doesn't make it a great idea I suppose.


But with the starter...it's prob hard to fuse it because of how much current it pulls? They def can be a dangerous spot on the truck if they get stuck on or short out. Prob been too many trucks burn down that way.

I'm with the fellas here...protecting against a dead short with a fuse on your main cables is a smart idea.
 
Alright, let's explore this. Let's say I put a single ANL fuse on the PS battery and have a dead short in the positive cable that goes across the core support. The fuse would blow and the batteries would now only be connected via ground path.

This also means that the DS battery positive terminal is no longer connected to anything unless the starter solenoid is energized. I could then have a dead short in the starter cable to the body or the starter solenoid could freeze closed. Either could easily cause a fire and is not covered under the proposed fuse arrangement.

Also, if my alternator goes bad and over-energizes the battery there's no fuse there, so the battery could feasibly explode.

This game of what-if is dangerous guys.


Another question. My batteries can put out 930CCA each. Doesn't that mean I need a 900+amp fuse?
 
I see the analogy as: ridding a bicycle is inherently dangerous. But if I'm wearing a helmet it makes some aspect of being on the trail less dangerous. It's not going to prevent a bear from jumping my hide but at least my head is protected when I fall.

Clearly you can't cover all aspects of electrical danger in your rig. But some things as easy as buckling a helmet.
 
The question is then "what kind of helmet should I wear?"

DS battery is grounded to engine, engine is grounded to body, so unless we're fused on both ends of the wire that goes across the hood, there's still a possibility of a dead short through the body.
 
To clarify my points here guys, I'm not trying to be combative, but if y'all honestly think that I'm going to burn my truck down I want to think about all the ways that my electrical system can burn down my truck and prevent them all, not just one. I obviously don't ever want to burn the truck down, I would be shattered.

Installing fuses or circuit breakers in these circuits is not difficult or expensive, I'm just trying to determine if it's needed. If OEM manufacturers don't install fuses on trucks with factory dual batteries, why should I?
 
GLTHFJ60 said:
Another question. My batteries can put out 930CCA each. Doesn't that mean I need a 900+amp fuse?
Click to expand...

Duh, no, because the cables can't carry that much current. Looks like the max current for 1/0 cables (what I used between batteries) is ~170A. That's what I would size the fuse/circuit breaker for:

http://www.usawire-cable.com/pdfs/nec ampacities.pdf

Repeat after me. Fuses and circuit breakers protect the wires. That's their only purpose. Rate your wire size for the current needed then rate the fuse/circuit breaker for the max current capacity of the wire.
 
woytovich said:
As Cruiserdrew said: "You have to fuse the big hot lead at both ends-right next to the battery."
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Right. My post above was meant to explain why that is the case.

woytovich said:
Warn does not recommend fusing their winches either... but you are planning on doing that if/when...
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Is that documented?
 
They do not mention fuses anywhere I have ever seen. I have not seen them specifically SAY it is NOT recommended either - and I wouldn't expect them to say that - lawyers being how they are and all.
 
woytovich said:
This thread for other perspectives: M12000 Winch - What Fuse to use?
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So along the lines of what I said earlier, your fuse is 500 amps, but what gauge wire did you use? If the fuse won't blow until after the insulation melts because the wire got too hot then it doesn't do much good.

Based on the charts I'm finding, you'd need a 750(gauge) wire to handle that much current and stay within the wire's operating range:

Ampacity Charts
 
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