boogyman

yes, i wrapped the wire in plastic electrical insulation, tucked it up and secured it under the lip of fender well in the engine bay

i meant an oversize fuse.. bad choice of words on my part.

was this confirmed by the original poster? I must've missed that post.

which vehicles were recalled due to this "problem"?

like i said, if it makes you feel safer, that's fine.. i never said you were wrong to do this, i just don't feel it's absolutely necessary.

i ask this: what's the maximum distance you can place a fuse from the battery? 6in? 1ft? 3ft? 10?

dz

I wasn't saying that any vehicles have been recalled, just that they probably would be if something like that were to happen.

As for fuse distances, "as close as practically possible" is generally a good distance to go with

L33T35T 4Runner

I'm gonna have to jump in on this one.

Putting a fuse as close to the battery as possible is the best thing you could do. as somebody stated, in a perfect world you wouldnt have to. but rats chew through wires, car accidents happen, and metal rubs insulation away.

so what if you only have a fuse near the load (say a CB radio) and the wire shorts out on the tip of a screw that you didnt know the wire was running by? goodbye wire, and hope it doesnt catch on fire.
again same scenario, but now you have a small 5 amp fuse with some 14 gauge wiring. again, that wire shorts out on the tip of that screw. wire shorts out, blows fuse, end of story.

i can sum this up in several words:

BETTER SAFE THAN SORRY, why take the chance of having that wire burn out and cause a fire. especially in a hot engine compartment with fuel lines and eventually a gas tank

what most likely happened was that wire got shorted out somewhere and the wire burned all the way from the battery to the short, since thats the easiest path for electricity to go, from the positive post back to ground. the wire isnt going to burn after the short because no power went through the rest of the wire, as again, electricity takes the path of least resistance.

theoreticly you COULD put a fuse anywhere in the wires, it will be the same measurable current draw anywhere in the line, positive side or negative, 2 inches from the battery or 10 feet, but as i said earlier, shorts happen

that's all i feel like posting for now

Jason - Certified Diesel Mechanic

4x4Lamm

Here is a pic to remind you to be careful with wires. The origin of this fire was a STOCK componet. The fuse obviously did not go before the circut became hot enough to ignite a solid combustable. My point is, after 10 years or so of rough driving, things can get goofed up resulting in a vehicle fire. As said before, there is a direct corralation between the inherent safety of an electrical circut and the proximity of that circuts fuse to the power source. Do you really want to chance this? If Toyota's wiring failed, yours certainly can.



NOTE: This is also a good reminder to have a good fire extinguisher)s), it sure would have sucked to sit there and watch it burn for 6 minutes till an engine got on scene.

Lamm

mt_goat

Lamm I remember seeing a whole thread about your fire, but I didn't notice what caused it. So what componet was it? Looks like you had the same dash as mine.

4x4Lamm

The determination the fire investigator and I (I'm a firefighter, and do some investigation myself) made was the wiring between the ignition switch and the fireall was the ignition point.

It was not any wiring I had a dded for sure, as all of my aftermarket wiring was on the passenger side, and I tested each circut and none showed significant voltage drop.

Lamm

NC-B17A

boogy o you got me I must not know anything about wiring because I misspelled a word. Dang my 15+ yrs of car audio install & me being M.E.C.P. certified back in 92 & the 100's of cars that I have done installs in have all been for naught :pat:
dude spreading misinformation does not help anyone.
4x4Lamm man that was a bad fire

boogyman

Agreed. If you look at my various other electrical related posts, you can see I'm not. Just because I disagree with your opinion does not mean it's misinformation. Please don't use the guise of "misinformation" to justify your opinion.

Edit: At least we can agree that there needs to be a fuse in the line somewhere.

boogyman

Yikes. Looks like at least some of it is salvageable though. I take it no one was hurt (hopefully)?

Erich_870

If a person feels completely confident about thier wiring set up, than they should do what they think is best, BUT if they were installing something electrical on someone else's vehicle they are risking some SERIOUS liability!

It's pretty hard to dispute that putting a fuse as close to the battery as possible, pretty looking or not, will significantly reduce the chances of anything causing a short.

It's the best practice to reduce the possibilities of short circuits, so recommending the fuse close to the battery is the best thing to do on a public discussion like this.

If a person decides to place the fuse somewhere else, after they've heard the best practice, well then they've made an informed decision. If anything does happen, they had the chance to prevent it.

Also, about the analogy with the water pipe... To me it seems fitting in both cases.

First, it's true about pipe networks.

Second, if you break a pipe above the valve, water will continue to flow until the reservoir is emptied. The DC battery in our vehicles is the same system. The current will continue to flow from the battery until it is depleted. I've heard AC current described as "self extinguishing" due to it's polarity oscillation. Now our DC batteries are designed to give all they've got until thier gone. So you've got to do everything you can to keep that "horse" behind the gate, so to speak.

My last question is, if a person puts in a lot of thought and planning putting together thier wiring, why skip the fuse at the battery?

Just my .02

Erich

boogyman

I could be wrong on this, but from what I remember, the frequency of the oscillation is too fast to self extinguish. Basically, when connected to ground, the AC current will act as DC current, and flow until the source is depleted or cut off. In the case of AC power from electric plants, the physical earth is the ground point, and electricty will flow from the source (wall socket, or wherever) to ground by any means necessary. Which unfortunately is how people get hurt playing with AC current in their homes :-(

Erich_870

That very well could be. I've seen over head power lines do some pretty crazy stuff to asphalt.

Erich

4x4Lamm

Yes, quite a bit was salvaged for my current 4Runner. A passerby saw it and woke me up and I was able to extinguish it in a matter of seconds, nobody was hurt at all. I estimate it brnt for 4 minutes, maybe 5.

Lamm

GSGALLANT

I didn't see any reference in your post about having an in-line fuse or breaker in your main power line supplying your aux fuse block. If you don't have one, you should look at putting one in (proper wiring practice). Of course, it should be sized no higher than the total rating of your fuse block. In keeping with the theme of this thread, place it as close to the battery as you can.

dz

AC is self-extinguishing in the case of a sufficient gap that an arc cannot jump in the first place, as opposed to DC where more seperation is needed to stop an arc. This is why DC switches and breakers need to be larger (more contact seperation and usually a higher opening/closing force) than a similarly rated AC switch/breaker.

mt_goat

That's interesting, that would also explain why DC arc welders work better than AC welders.

firemedic

In theory it doesn't matter how far your fuse is from the battery. In real life it does, all the manufacturers put fuses close to the batt for a reason, even in a controlled manufacturing environment there is to much chance that a short will eventually occur and the car will burn to the ground. I have put out several car fires that started because of aftermarket stereo wires that weren't fused near the battery, starting a fire under the dash. Always put your fuse near the battery. If you don't think anyone needs to do that than you must also believe that vehicles never have OEM wires that short. Any mechanic will tell you they have spent hours trying to find shorted wires in OEM applications, think how much more likely the wire you added, will short, over the life of the vehicle.