leo3000

OK...

ive been told multiple times i need to put a relay with my new fog lights (walmart 55watt bajas). After doing some reasearch and trying to figure it out on my own, i decided that relays move all the higher amperage wires to the engine compartment and allow you to run a low amperage switch which is safer because you dont have any high amperage wires in the dash or inside the vehicle. I dont even know if thats what they do, but after reading i think thats about right...

BUT

then i saw this site:http://fitchva.com/jeep/?p=47 this guy put all his relays inside. wouldnt that defeat the whole purpose of relays?

Now, i just went out to the autoparts store and got a relay and some wire and connectors, im planning on wiring it using this:

BUT, i have no idea what the wire that goes from the switch to the fuse box is or does or anythng haha

well, i may be wong with everything on this thread lol, but i obviously need help

so thanks in advance for any help and im sorry there are so many noobs in this world haha

thanks

JSwamper

Dont go by that scematic....
You dont need an indicator light,, or even run line to your fuse box,,,

Do everything in that picture, except for The indicator light, and the fuse box/

JSwamper

depending on how many light you have use,, use 12-10 gauge wire,,maybe 14 if you only have two lights

leo3000

sweet thats exactly what my plan was, where would i run the thing that goes to the fuse box?

leo3000

i just bought 16, im running two lights, whould i get something else?

JSwamper

that is a switch running to the fuse box, honestly i don't understand that because i didnt do it that way.

from your swtich, run one wire to your battery and the other??? i think ground it

JSwamper

16gauge is too small and the wires will get hot and burn out your fuse,,, and if you dont have a fuse it will burn out your lights.

JSwamper

from your swtich, 1 to the battery , the 2nd wire goes to the relay

storm101

The fuse box wire can run from there or the batt it is what you could think of as signal to turn the relay on which makes the internals click to let power run from the batt wire connected to the relay on through to power the lights i actually made a post last night with an idea i came up with last night....it should be new still and theres a diagram i made in it , check it out if youre interested

4.3L XJ

A couple of things here. Before we start, I have extensive experience with relays of many sizes from 5- 200 amps of service (200 amps is what feeds a house.)

First, a relay is a switch that can be used to switch a heavy or light electrical load.

Second, it can be mounted anywhere and they come in various configurations and sizes.

Third, for 55W lights you don't really need a relay.
The standard formula for watts is: Volts X Amps = Watts
A little high school algebra gets you Amps = Watts/Volts.

In this case you have Amps = 55/12 = 4.5 Amps X 2 = 9 amps

The number of amps is what determines wire size. There were several sizes mentioned above. 14ga is almost very sufficient here as it will handle 15 amps, and is what I would use. Any heavy duty Carling Switch, which will fit in your stock fog light switch position will handle that. Where you hear about relays and need them is when running multiple sets of lights or high wattage. For instance, three sets of those 55W lights gets you about 54 amps. For this you need a relay or better yet two.

prerunner1982

Using a relay will also keep the wires to your lights shorter which will have less voltage drop rather than running 5' of wire into the cab and back out. Though the voltage drop created when not using a relay..... may not even be noticeable. I have not tested the setups to know the exact voltage drop figure between the two. I like to use relays on everything, just to be safe.

prerunner1982

Since he has a large gauge wire from the battery, then the setup as he has it works fine except the wire from the box to the accessory would be fairly long. If the box would have been mounted in a more forward/middle position (I would think most "switched" accessories are on the front) I think it would have been better, say under one of the seats.

leo3000

thanks everybody!

Skater28

If you don't use a relay just make shure you use a heavy switch. If not it will burn. Thats why you use a relay so the relay carries the load that the lights draw and it dosn't go through the switch. Also if you decide to use a relay it can go in or outside your jeep as long as the wires from the batt. to relay and relay to lights are heavy enough

marc_41_745

the voltage drop will be so small that a meter wont even notice it. your not running 1200 feet of wire so you wont have to worry about it. from the 12 volt battery you might get 11.99999999 volts. thats how small the voltage drop would be. i would use the diagram that was shown. its easy to follow and makes since. just try it that way. if you really want you can remove the indicator light, its not needed