by request ive started a new thread with a more easier to search topic.

How can i wire my jdm fogs (4th gen) to my headlights so that when my corner lights come on my fogs do too?

 

yea how would you wire it so you dont need the button?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by evolvedbb2 &raquo;</TD></TR><TR><TD CLASS="quote">... to my headlights so that when my corner lights come on my fogs do too?</TD></TR></TABLE>

does this mean u want to just hardwire them to ur headlights?
if so then just splice them right into the headlight wires.

or did u want to hardwire them to a new fuse that turns on when the parking lights turn on? (because hooking them up to the parking lights will cause problems)
if so then u could go through the firewall and hook the + to an unused fuse in the fuse box that turns on when the lights turn on (i would also use an inline fuse if u go this way)

or did u want to modify the relay so that it would work with the switch when the corner lights are on (in that case u could hook them up to turn on whenever u want.)
if so then u would need to modify the red/white wire going into the relay to the appropiate source.

 

i want the easiest way to wire them up but dont want to cause real problems..

 

DONT hardwire them into your headlights. The easiest way is to use a heavy duty relay or a pair of medium duty relays. All you need to do is use the +12V supply for the headlights as the "switch" on the relay. Run the other output to the foglight, and then use battery power for the input voltage. run the ground to the chassis near the relay. done.

 

hey bud i told you all this in your last tread but here you go.

im assuming you want them to come one with you running lights and stay on with high and low beams. no switch involved.

your not going to uses the factory wiring except for the ground for the fogs. your going to need a relay. i used a five prong one is for the power from the battery, switching source, ground and the two power wires for the fogs. im not going into how relays work so ...find a place to mount the relay and run your 12v power source i just ran it directly from the battery. your switching source is up to you. i used my corner light power wire because it comes on with you running lights and doesnt blink! run the power for the fogs and i grounded them through the factory harness. hope this helps AGAIN
JOE

 

my only problem is not sure how to USE a relay.. thats my problem..

 

Go to "prelude3g.com. There ia a write up (with pics) detailing how to re-wire the fog light relay to allow the foglights to be used with parking lights instead of just with headlights. It might apply to 4th gens too. It's pretty simple and has been done to many, many 3rd gens. ( I wrote it )

 

thats cool and all but how do i use a relay?

 

If you are refering to my post concerning the re-wire writeup. You don't have to "use" a relay. You just rewire the one that's already there.

 

Get a Mitsuba RC-2225 relay and you can either jump the green plug or wire up a switch to it.

I used a 5th gen switch in place of my cruise switch (same just different face) since mine is removed.

 

can someone quickly explain to me what a relay does maybe that'll help me get this..

 

i will explain a basic 4 terminal relay for you:

a relay is an electrical device used to turn something "on" when something else is turned "on". so when your headlights come on, the relay will trigger the fog lights to come on. take some time to re-read what i just wrote untill you fully understand what i mean.

inside a relay, there are 4 basic terminals that you may attach wires to. there is one terminal that powers the relay to "switch" on. we'll call this "terminal A". in your case this will be the (+)wire that powers the headlights. another terminal is used to ground your triggering power source. we'll call this "terminal B". you can use any wire for this terminal in your little project and just ground it somewhere. the 3rd terminal is used to power your fog lights. in case you haven't figured out my clever method for naming ternminals, this is "terminal C". someone mentioned that you should use a 12V power source like your battery for this terminal. this wire will send 12V of power to your fog lights when the relay is switched "on". 4th terminal sends the power to the fog lights when the relay is switched "on", this is "terminal D". run a wire from this terminal to each of your fog lights.

ok take a deep breath and make sure you understand what i just said. so the headlight wire triggers the relay to turn on, and the ground wire grounds the headlight wire (this completes the circuit so the relay will work). then 12V of power from the battery are sent through the relay when the relay is switched on. and finally the 12V of power are sent to the fog lights. oh yeah, and make sure youground the fog lights too.

i am horrible at writing step by step things, but you can probably search this kind of stuff on google or something.

 

here is a good link:

http://electronics.howstuffworks.com/relay1.htm

 

thats sounds like a pain to do... can u not just wire into the corner lights and add a fuse somewhere?

also on a 4th gen other than wiring it straight to the battery where else could i pull the 12v source from?

 

you could tap directly into your headlight wire. you wouldn't need a fuse either. i'm not sure, but i don't think the light will be as bright if you use a wire thats meant to power headlights, and try to make it power headlights AND fog lights.

there is a difference in knowing WHAT you are doing, and knowing WHY you are doing something. its really not that big of a pain if you understand why, and what you are doing. do not attampt this if you are not comortable with electronics. just know that you are already splicing into your wires, so why not just do it the right/best/cleanest way? total supplies shouldn't cost you more than $20 total.

another 12V power source can be found on your fuse box. if you follow the + cable on the battery to the fuse box, you can wire your relay in there. you can also find a spot on tour fuse box that says "ignition", you can use that wire, but you will only get power when the ignition is turned "on". this comes in handy so you won't accidentally leave your fog lights on. do not attach the fog lights directly to the battery unless you are using the relay method! your fog lights will stay on the all the time!

 

A very good place to draw 12volts from is the big bolt located on the starter solenoid. The battery + side battery cable goes on this so attaching a wire with a ring connector will be like getting juice directly from the battery except neater.

Another way to look at a relay is that it's a mechanism for controling a heavy amperage circuit with a very low amperage circuit. If you just use a simple toggle switch with no relay for foglights, it had better be a heavy duty one or it will burn your fingers.

If you are wanting to completely wire the foglights and not use any of the the factory wiring, you should connect heavy wires for the + side foglights to the starter solenoid connection explained above. Route the - side foglight wires to a relay SWITCHED side terminal. The other SWITCHED side terminal, of course would go to a good solid chassis ground. The SWITCHING side of the relay can be attached to a + 12v wire from a parking light circuit. I would also throw a dashboard switch on this circuit so I could switch the foglights off if I want.


Modified by GlenWatkins at 9:53 PM 7/10/2006

 

ok so do i need 1 relay per fog or 1 relay for the set and what relay do i need 4 pin? or what?

 

No..you only need ONE relay for both lights. The relay should be controling the ground for the lights rather than the hot wire.

Yes a 4 pin relay is what you need. Be sure it comes with a diagram that identifies the terminals. As explained above...there will be the SWITCHED side terminals and the SWITCHING side terminals. That's probably not what they will be called on a diagram but you get the idea.

 

ok you confused me in your post.. the relay should control the ground? why the ground? tell me if this is how its supposed to work..

Power to Relay from (12v source like battery) then splice into corner lights from relay then wire in the power to fogs then ground fogs?

 

Sorry to confuse.

Ok, lets go thru this slowly.. Your foglights need a heavy duty +12V supply. (white wire) they also need ground wire (black). You can switch the foglights on and off by interupting either the +12v supply wire or the ground wire. All lighting circuits are controled by switching (with relays) the GROUND wire. It's just safer.

More to come

 

The foglights ground wire (both spliced together) will go to either of the SWITCHED side relay terminals. the other SWITCHED side terminal would be wired to a good chassis ground.

To control the relay, you would want to splice into a parking light +12v wire to the proper SWITCHING side terminal (a specific one, unlike the SWTCHED side terminals) To complete the SWITCHING circuit the other terminal would go to a ground.

Wired like this...when you turn on your parking lights, the SWITCHING side of the relay will be activated and will throw a set of contacts that will supply ground to the foglights turning them on (they will ALWAYS have a +12v power supply from the battery)

Like I said above, I would add a dashboard switch on that last SWITCHING side ground wire in order to shut off the foglights if I want.

 

whats wrong with doing the power wires instead of switching the grounds on and off?

 

Nothing really. Switching the ground is just a convention.

Oh..I see, you want to use the factory ground for the foglights. That's fine if the factory ground is an actual chassis ground. You may find that Honda uses the foglight ground to CONTROL the foglights.

You might want to search the websites for aux light manufacturers like Pilot, Piaa, Tucan, etc. They may have a wireing diagram you can use.

You might want to invest in a $10-$20 volt/ohm meter.

I realize this all sounds like a big "pain" to you and I'm sure you expected someone to give you a 15 second solution..


Modified by GlenWatkins at 12:17 AM 7/11/2006


Modified by GlenWatkins at 12:28 AM 7/11/2006

 

invest in the relay...your headlight harness wasnt meant to run both headlights and 2 foglights...at best, you could blow a fuse. at worst, you could melt the harness and possible cause an electrical fire. take the car to someone in the know if this is too much for ya. its not worth your car to cut corners....