ok here we go........ive wired EVERYTHING possible into a car. From headunits to mini fridges ive done it all. However everything ive ever done was hooked up directly to a toggle switch..........i was thinkin of tossin some basic fog lamps on but i want to set them up with the headlights using a relay........i want the fog lights to go on with the headlights......can someone draw me up a quick diagram on how i would go about doing this. Do i just tap into the headlights? I kno its prolly easy but i just wanna make sure. Thanks Pete~

 

I only have the exact wiring diagrams at work, but if you have a volt meter, it should be easy. Find the headlight wire. Now test if it goes to 12V when they're on or GROUND. I know that the idea of GROUND when on seems stupid, but some cars do this. Now look at a basic 5-point relay. If you don't have one, email me. I'll send one to you. Just pay me for shipping. There are five male quick disconnects on a relay. If you look at them, there should be numbers next to each one. The numbers WILL be 85, 86, 87, 87a, and 30.
Now a basic summary of how these relays work:
30 is normally connected to 87a when at rest. When 85 and 86 complete a circuit (85 on 12v - 86 on ground, or vise-versa) 30 moves from 87a to 87.

so if you want to hook up fog lights to headlights, there should be two wires off the fog lights, red and black, or something and black. Ground the black wire to the chassis. Run a wire from the red wire to inside your car under the dash. Hook that up to pin 30 on your relay. Hook up pin 87 to 12v CONSTANT, not switched. (No big deal, it's just if you want the foglights to go on with an alarm or something, they won't unless you run the ignition first). Leave 87a empty. If the headlight wire is positive, hook it up to pin 85 (using t-tap and two female quick-disconnects on a wire), and hook up 86 to ground. If the headlight wire is ground, hook it up to 86 and hook up 85 to 12v constant (you can use the same one you used for 87 if you neeed to do it this way). If you need some help, ask me. If you need the relay right away, go to a best buy, or circuit city, or good guys and ask for a basic relay with 85, 86, 87, 87a, and 30. They'll know what you're talking about.

Hope I could have been of help.
Josh

 

ok i have got the concept...........but when u say "If the headlight wire is positive, hook it up to pin 85 (using t-tap and two female quick-disconnects on a wire), and hook up 86 to ground. If the headlight wire is ground, hook it up to 86 and hook up 85 to 12v constant (you can use the same one you used for 87 if you neeed to do it this way)."........................then couldnt i just choose the use the positive or negitive wire to tap off of?

 

Ya... you could. It might work, but sometimes that has weird effects if the headlight wire doesn't push enough amperage to the fog lights, because if it's just a wire that switches a relay in the fuse box under the hood (which it does) it might not have enough amperage to run those fog lights of yours. Try it that way, if they are a little dim, throw the relay in. I just checked my tech sheet for my car (2005 SI) and the headlight wire is positive. Yours probably is too. Try it that way to save time.

 

pcu what year do u have?

 

94 ex..............lol this relay **** is confusin me.....can someone draw me a diagram? LOL it would be appreciated.

 

This is gonna be hard, but I'll try

----------------------------------
| |
| |87 |
| |
| |
| |85 |87a |86 |
| |
| |
| |30 |
| |
----------------------------------

This is a basic model of a relay.
Those lines next to the numbers are the male ends.
when 85 and 86 complete a circuit (positive {12v} to one and ground to the other),
whatever was hooked up to 30 moves from 87a (where it connected resting) to 87
So if you want to throw power to your fog lights, ground the black wire off the fog lights, and hook up the positive to pin 30. When the circuit is not connected and the relay is at rest, it will be connected to pin 87a. Leave that pin empty, because when you don't want the lights on, you want the red wire connected to nothing. When the relay activates, it (red wire connected to pin 30) will jump from 87a(nothing) to 87. So 87 should be hooked up to a constant 12v source (preferrably off the ignition). Now to activate the relay, ground pin 86, and hook up 85 to the headlight wire. If I were you, I'd actually try what you suggested, pulling the 12v off the headlight wire directly. It will save you a ton of time, and it might work well. Just do this if the headlights or the fog lights are too dim.

I hope this helped,
Josh

 

okay, the picture of the relay didn't show up right, but the pins are in that arrangement.
sorry

 

lol use PAINT and try something easier understood.

 

dude, where do you live? if you are anywhere near my shop, I'll hook up your fog lights for you, then we can also talk civic stuff.