I hear ya man, I don't want to argue either, but the statement that was made was which is wrong, there will be more current. I never said that it would be excessive, but it will absolutely be more, and will increase more and more as wire size increases. I too am a fan of running wire that is a tad bigger than necessary, but there is a point where it becomes overkill and will have a negative affect. As I mentioned before, I've seen this happen first hand, and it's not a pretty sight. Try running a 10ga wire to a PCM and see what happens...

 

Weeeeeeeeeeeeellll if you want to prolong the discussion, if we consider the battery as a current source then current would remain the same while voltage drop would increase as the resistance falls....but a battery is much closer to a voltage source (especially lead-acid batteries), so my comment wasnt totally wrong, but could have easily been omitted to avoid confusion.

 

Billy, think about this. There's a positive wire to every major component in a vehicle...but the negative goes to ground, or the vehicle itself. If you think a 0 gauge wire is big, think about the conductivity of an entire chassis. Just because there is more of this metal does not increase the current in the circuit to the extent which would blow fuses. As Richard said, the power dissipation in a circuit is directly proportional to the resistance, and proportional to the square of the current. Excess power dissipation in part of a circuit that is not meant to dissipate power (read:heat) is what melts wires and blows fuses. Resistance and current have different variables in this power equation: P=I^2R. Given a constant power source, decreasing resistance (ie increasing radius of the current-carrying wire) does increase current in the circuit, but inversely proportional to the decrease in resistance divided by the total resistance. The fraction of total resistance in the wires of a circuit is very small, most often negligible compared to the resistance of the entire circuit. Therefore decreasing this wire resistance by using a heavier gauge, the resistance becomes even more negligible, as does the increase in current. Hope that makes sense...

 

Well, it all makes sense on paper, but I have to go back to what I've both seen and taught through the years. In both GM and Toyota schools, we had these cool project boards that we used to teach/learn the basics of Voltage, Resistance, and Current, where we could see the effects of changing resistance and source voltage first hand. I simply stated that increasing wire size increases current, and meant to convey that a bigger fuse may be required, and two of our members replied with saying that decreasing resistance has no effect on current, which really got me concerned about what people are doing here.

I'm not really sure about the point that you're trying to make about the battery Richard, a battery is a voltage containment unit, and voltage is pressure...

I guess that I should have stayed out of the discussion and introduced the basic electrical theory that I feel we all should know before we go stripping wires and adding extra components to our vehicles. Maybe I'm just a little over-cautious because I've been in the field so long and seen so much crazy **** that it makes my head spin, and feel that people should have a little knowledge before venturing into projects. Sorry, my bad.

You guys continue, and I'll delete my posts if you'd like...

 

Keep your posts, you bring up very legitimate points. I think the confusion is coming from a sense of scale with what real numbers are....yes bigger wire will increase current, but how much? Not enough to be able to measure without really expensive equipment and certainly not enough to make any difference in regards to fuses would be my answer. So for all practical purposes, changing the wire size will not alter the current load.

 

I'm sure what you were taught was correct, but electricity is a little more dynamic than most realize. In the Air Force, I was in a course called electronic principles, and it just covered the basics. Just the stuff that you absolutely need to know to be able to maintain equipment. Now as an electrical engineering major, its easy to see they were just scraping the surface, and for good reason. Maintaining equipment or vehicles doesn't require engineering, just the basics. To be able to completely describe this particular piece of circuit theory, it would require physics, materials science engineering, and electrical engineering. It's pretty complex!

FYI, a battery is an energy containment unit, with units of Joules.

 

Allrighty...I came back on here to delete everything from my first post on, but I guess that I'll keep em, good discussion. You bring up a good point when you mention the scale of things.

Ahhh, I thought that I said the wrong thing, and then made it bold and italicized lol, thanks man.

After all this, did the OP (of this scenario) ever figure out why he was blowing fuses? Kinda got off course here...

 

I go back to my original assessment of he wired it up wrong

I made another fan harness this weekend for my new truck and used some bigass 10ga since I had a surplus of it.

Just for ***** and giggles I measured the resistance of a small piece of 10ga wire and an equal length of 16ga wire and my $50 voltmeter couldnt read a difference on the lowest setting.

 

If Quik weren't banned he might get on here and tell you that you hooked up the multimeter leads backwards

 

hahaha