Relay Wiring Question...Am I Making This Too Hard?
 

Ok, so lets say that youre wiring some fog lights into your car, and you want to use a relay like a good little boy or girl, and you know how to do that with a switch and all no problems. However, doing it normally isnt good enough for you because you're an over-achiever and need to do something cooler than the next guy so you decide to use a 3 way switch to wire them up. This way, you make one position ON, one position OFF, and one position ON with the highbeams. Get it? This way, you can be crusing around with your lights in any various configuration. Say youre out running around with your high beams on and you only have an on/off switch and you see a car coming your way, you dim your highs but still have driving lights in their face, not cool. My idea would prevent this from happening by turning off your driving lights with your high beams. Or, you could have the option of running with them on instead of headlights at dusk like some people like to do, or whatever. My question to you, is how do I do this? I mean, the last 3 way switch I played with was simple, three terminals. Power goes in the middle, and out either the top or bottom depending on which way it was toggled. So, assuming you have that type of swich, you would simply build a relay circuit for the lights as "usual" for the ON part, but when you flip it to the ON with hig beams part, you have 12 volts coming out which is more than ready to trigger a relay, but how do I make it trigger the relay ONLY when the highbeams are on? :confused:

Is it really that I need to make one realy for the high beam circuit so when it gets voltage, it triggers another relay that lets the voltage from the switch trigger the original relays for the ON position? I dont know why, but this is really baffling me for some stupid reason... I havent been able to concentrate for crap lately, I think I have ADD or something, lol. Anyone got any ideas?

~T.J.

wiring
 

TJ...the attached circuit diagram should do what you are looking for.

Ok, lets make things more complicated... Im adding 6 lights, using 3 relays. Heres what I whipped up for my idea, I didnt take the time to make any fancy symbols, but I think you get the idea.

The red is battery power, black is ground. The yellow is power to trigger a relay, and the cyan is the output from the relay. Blue squares are relays, yellow boxes are switches. The small one in the upper left is supposed to be depictive of the high beam output, the other is the three way switch, and the magenta circles are the lights.

Heres what Im thinking... The switch is in the ON position (bottom yellow line), so it triggers all the relays and lights the lights. Now, when you put it in the on with high beam position, it passes the power from the switch into a relay as the power INTO that relay. Then, when you apply power to the relay from the high beam switch, it lets the power from the dash switch go "through" and then becomes the TRIGGER for the second relay, which has power coming from the battery which then goes "through" the second relay to TRIGGER the original relay bank from when the dash switch is in the ON position. Does that make sense?

~T.J.

EDIT: Basically Im trying to acheive wiring a switch that will allow me to have the lights on, off, or on with highbeams. But I dont want them to always come on with the high beams, hence the off position, so the high/low beams will still operate normally with no driving lights when the dash switch is off. However, I want to be able to turn them on whenver I want reguardless if the high beams are on or not, lol. Wow, Im starting to confuse myself...

https://www.rx7club.com/forum/attach...id=87243&stc=1

think you could add lables to the graphic? it would make it a little easier to understand

Fog Lights
 

So you want to be able to switch your lights on/off regardless of whether your high/low beams are on? If that the case wire directly to the battery, through a switch to a relay the output of which feeds all 3 pairs of lights. I'd think a 30 amp relay would be heavy enough. just be sure to put a fuse at the battery so if you get a short yu bon't start your truck on fire.

This is the way to do it.

https://www.rx7club.com/attachment.p...chmentid=87323

Did you even read his requirements?

Alright, I think I know what Im trying to do now... Between what Im thinking, and what has been posted, I think I have a good idea of how to try it.

~T.J.

The diagram I made up will do exactly what you said you wanted.

Yeah, I did read it...an excerpt from the "Edit" portion of the last thread reads....."a switch that will allow me to have the lights on, off, or on with highbeams." That basically means he wants to be able to turn the lights on regardless of the condition of the regular headlights. The simplest and cheapest way to do that is exactly like I said...wire directly to the battery. Your way will work, in fact it is just a more complex version of what I drew. The difference is you are using the lighting supply as a source for the relays, where I went straight to the battery. Why go to the added expense and frustration all the while risking an overload on your regular lighting circuit? Simpler = more reliable. What a concept.

Obviously you didn't read it. He wants to be able to turn the fog lights on by themselves OR have them come on with the highbeams.

Also, there is nothing risky at all about the diagram I drew. There is no risk of overloading the regular light circuit because all it's doing is triggering the relay when you turn the highbeams on. If you read the diagram again you will see the power for the foglights is coming from the battery. That's the whole point of having a relay.

Simplicity is good but what use is it when it doesn't actually perform the function you're after. :D

You an electrical engineer or something? Yes, I did notice power for the fogs is coming direct from the battery. That is the correct way to do it, otherwise you WILL definitely overload your lamp circuit!

As for having the fogs by themselves or with high-beams....why? I spent a considerable part of my life in the San Joaquin Valley in California, where the fog gets so thick you can't see past the hood of your car. (and people still drive 70 mph on the freeway??????) Trust me high beams is the last thing you want in the fog.

Furthermore, a relay draws current....and 3, as depicted in his original diagram, draws 3 times as much. I've seen computers and alternators fried because of simpler things than this. To say "there is no risk of overloading the regular light circuit", those are the kind of people I regularly clean-up after.

So now you're telling how he should configure his own fog lights? If he wants be able to switch them on independantly or with the high beams that's up to him.

A typical Bosch automotive relay draws 0.160amps. On my circuit he can add as many relays as he wants to the fog light output and the current will be drawn from the battery. The most that will be ever drawn from the headlight circuit is 0.160amps. I'd love to hear how this will overload it. :rofl:

revhed's circuit is perfect for what you explained, however i would add another relay just before the fog lamps that was energized by your accesories circuit. this would ensure that when you turned your car off, your foglights were off when you have you spdt switch set to "dusk". Have fun and let us know how much it cost and how it went.

Dude, I'm not here to argue with you. I know this person (vaguely), if he doesn't agree that's fine. He is plenty capable of making that choice himself and if he wishes he'll ignore my input.....kind of like I'm going to do with you henceforth. But first, while I'm not an electrical engineer, I do have a considerable amount of experience in this area and as I said a big part of my job comes from cleaning up after people with this same attitude. Answer this genius....where did he ever mention a Bosch automotive relay? I regularly use relays that draw upwards of 2 amps. Try putting even one of those on your lighting circuit and tell me what happens. People who speak in absolutes often end up eating their own words...and then calling me to clean up the mess.

Bottom line, I will continue to offer my input, particularly since I do know him. I don't require your approval or ask your permission to do so. I would hope people would tell me if there might be a better or more cost effective way to do something I were attempting to do, especially if it might prevent damage to my car...or truck in this case (?). You didn't really think he was talking about an RX-7 did you? Who puts 6 fog lights on an RX-7?

'Nuff said.

You made it quite clear from your posts that you aren't an engineer of any kind. :rofl: Could you please enlighten me as to what my atitude is? I'm an electrician and work with electronics and relays every day for a living. I can assure you that you would not be cleaning up after me in any way shape of form.

I was citing that as the typical current draw of a relay one would use in this situation. If you like to use parts that aren't suitable for the job that's your business.

The bottom line is this... I offered a solution to the question that was asked by the starter of this thread. There is nothing on the circuit I posted that would pose a risk to his car in any way (hopefully everyone has enough sense to add fuses where appropriate). You on the other hand have offered nothing and by getting personal have made yourself look even more stupid.

Also, I think the pics of the truck in his avitar and sig make it quite obvious which car they are going on. lol

I can simplify the circuit if the low beam filiment turns off when the high beams are on.

So uh, I recovered from my retarded state and I figured out last night (oddly enough in a dream - is it bad when you work on cars in your dreams?), I only need one relay from the high beam switch to make it work, so I know what Im doing now.

As for having them on with the highbeams and what not, theyre not for fog at all, theyre driving lights, not fog lights, so I wont be using them in the fog. The placement on the vehicle is ALL wrong for fog anyway, far too high off the ground as they are in fact for my truck, I just knew people here would be able to help me with the questions I had.

Two of the lights will be on my brush guard, the other 4 on the roll bar, so they will primarily be used off-road when I go 4 wheeling. The ability to have them on would be for when Im on a trail and just need lighting in a specific area and not so much in others (they will face different directions), and the high beam function would work well when I expect to encounter other vehicles coming at me as on the "roads" getting to the trails, that way I can douse the forward lighting by simply flipping one switch (high to low beam), as opposed to that switch along with three or more others on the dash somewhere. The quicker I can get the lights off, the less time there is for a mistake on the other drivers behalf due to my blinding him. And trust me, six 150 watt lights plus high beams coming at you is a lot of light to blind you and miss that tree rut that can cause you to slide off the trail on that precarious slanted ledge you were just wheeling on. ;)

Anyway, thanks for the input guys, I really appreciate it!

~T.J.

PS - Someone mentioned cost. I plan on spending around $150 for the six lights (which include 3 wiring harnesses with relays), and then whatever else on switches, wire, solder, heat shrink tubing, terminals, a relay, maybe an additional fuse block rather than in-line fuses, etc. I can probably get it done for around $200 actually.

I believe it does. Whatcha got?

~T.J.

I dunno if this is what you had in mind but this another way to do it. A bit simpler.

https://www.rx7club.com/attachment.p...id=87566&stc=1

Thanks again guys. I just have one more question, has anyone seen an add-on type fuse box I could put under the hood somewhere that would be semi weatherproof/waterproof, or just anything in general thats an addition fuse block not neccessarily weatherproof/waterproof I could put in the cab somewhere? I need something with at least 6 circuits that uses readily available fuses that can be had in ranges from 5 amps and up. I plan on adding quite a bit of electronic equipment to the truck overtime, so I would like to have the fuse block so I can dedicate circuits to the items rather than in line fuses.

~T.J.

Nevermind. I re-read your requirements...

I was going to have the fog/driving lights on with the low beams and off with the high beams, or off with the low beams and on with the highbeams... Dependant on switch position.

Easy add on. I know its your truck, but a 2gen fuse bow has 6 outlets and will work perfect for you.