i have some led bulbs (checked te forum for previouse led conversions)
i placed one on one of the tailights (no resistor to use up current) the turn flash flashes normaly but when
i try to turn on my lights, to parking light mode or full headlights, it burns out the fuse for that tailight and the low level light won't work
nighther the regular bulb or the led, but the turn signal and break still work

just wondering why a blub that takes much less current keeps burning up the fuse? i also tried placing it in the break light position
same thing happnes

 

k...

imagine you had taken out bulb and shorted the cuircuit... would you expect the fuse to blow?... duh! right?

so instead you have taken out the bulb and put in an led that draws only very slightly more than that short cuircuiting wire and are shocked when the fuse blows...

please explain why?

*winkz*.. don't mean to be a dick but this is wiring 101, and if you do not know it you should probabliy stay away from your trucks electrical system...

 

its an led bulb, doesn't it draw significantly less then the original 3157 bulb?

its only fuse 14 or 16 blow one left one right, turn signals and breaks work

i didn't put any resistors, just the led bulb from eurolite

similar to this http://getdieselpower.com/my04dodge_files1/led/

exept no resistors, so doesn't draw much power

and sorry if i sound like a noob but can u help me out then why is this truck so diffrent? other vehicles don't blow the fuse in similar situations

 

So are u saying the led bulb is making a direct short?

 

V=IR
Voltage = Current * Resistance

Voltage is constant in this system.

A bulb or led is really just a resistor.

So you replace your conventional bulb with a more efficient LED and your resistance lowers. Which means to balance the V=IR equation the current must increase. You need to add an additional resistor, available at Radio Shack, in line to equal the resistance of the stock system.

For example in your 12V system.

V=IR
12V = 10a * 1.2 ohm in the stock system.

If you now have a .5 ohm LED as a resistor the equation balances to this.

12V = 24a * .5 ohm

If your LED was actually a .5 ohm load you would need to add a .7 ohm resistor in line.

This is a good learning experience to go through. The basics of electricity. I took intro to circuit design as an elective a while back, really interesting class. Any further than this though and electronics gets pretty complicated, waves, programming, controllers and such.

Disclaimer:
These numbers are all purely made up, I don't know what bult or led has for ohm load. I also am not a electronics expert. I am pretty confident in V=IR and my calculations though. If I'm wrong whatever. If you flame me, whatever, **** off.

 

HemiBuell is correct.

Ohms law is V=IR and is incontrovertable.

 

basically what i said... just y'all were nicer about it... sorry i was in a foul mood yesterday.

 

As my physics teacher explained it to me (ok not really, this is how he should have explained it to me)...

Imagine a circuit is a path, from one place where people are, to another place where they really want to be...

imagine that the electrons are people....

logically the shorter and directer the path is with the fewer difficult to navigate spots, the more people will use it.

Imagine a fuse is a bridge... it is set up to allow a certain number of people over it at a time.... if that amount is significantly exceeded the bridge breaks and the path becomes inpassible.

Imagine the pathe chrysler set up for you... on the scale of things it is fairly difficult to navigate (high resistance) and only the rugged outdoors types will take it because there is a mountain (your bulb) halfway through it...

you took out the mountain and put in a moving sidewalk (LED... note a moving sidewalk is one of those escalator things tht they have in airports that stays on one floor)... now all the little schoolchildren, pregnant women and grand parents with walkers can easily navigate the pathe, and so do...

your bridge gets over loaded and breaks (fuse blows)... good thing too because all those people careening along the path were starting to tear it up. (excess heat)

solution?... put in a couple fallen trees and a water hazard (resistor)...

As to why your other vehicles had no problems... probably because their paths were designed for more traffic (lower gauge wires)... and had stronger bridges (higher amp fuses).

As to V= I*R

it can also be expressed as I=V/R

where V= the desire of people to get home, also known as potential difference or voltage
I= the number of people on the path
R= the difficulty of the path to navigate.

so... the number of the people on the path = the level of their desire to get where they are going divided by how hard this particular path is to navigate...

in a car "desire" is generally 12, and is therefore constant and can be ignored (as can all constants, usually a nice side effect of that is that E=MC^2 can just as easily be E=M or enegy = mass, so long as you get your units right)... and the statement can be simplified to

number of people, is inversly proportional to difficulty...

the more people on your path, the more over loaded the bridge...

the more over loaded the bridge the quicker it fails...

 

well explained, i feal 5 years old again

one other thingthat bothered me regarding that question is

when the fuse blows, the rear driving lights and the front driving lights for the same side( the turn signal in front on low level) they share the same fuse cuze it stops working too

i tried placing the led bulb in that front headlight, and it works in all positions withought blowing the same fuse( rear bulbs are standered non led)!

now how is that possible? or is it cuze of the way the way the tailight harness is desighned? harness i mean that plastick thing that holds all 3 bulbs, i want to add resistors, i don't know where to add them because i need them only for the driving light position? cuze having the 3157 is like having two bulbs cuze of the dual filament or the led 2 mods

also a note that if i place the led in the front headlight the turn signal flashes fast, and all works no fuse blowing
but at the back it blows the fuse for running lights, but turn signals don't flash fast

 

A bulb or led has power going to it and a ground wire leaving it to form a circuit. I believe you just need to equalize the resistance through the circuit. So you can add the correct resistance inline either on the power side or the ground side.

I would assume that the blinker needs to see a certain resistance for the timer to work correctly so a fast blinker has the same cause as fuses blowing.

I believe kits are made so it is just a plug and play to add resistance in line. I even have seen one that has a potentiometer on it to adjust the resistance. Like the way you adjust the volume on a stereo ****. That way you can dial in the blinker speed just where you want it. Check out stylinconcepts or similar places.

Same disclaimer as before. I live by the measure twice cut once mentality so do your homework before you take random opinions off of the internet. I could be some 10 year old just learning to type for all you know.