Headlight wiring \ driving lamps

[mattocs]

I was wondering if I could rig up some driving lamps I just bought to come on only when my high beams are on.

 

So my question is, the plug that powers the normal headlight bulbs, are one of those wires only powered when the high beams are on, and I can splice into it for the power of my driving lamps?

 

 

Does this make sence? Any better way to do it?

[NOMAD327]

You need to use relays to control auxilliary lights as the regular factory wiring and switches are not designed for the extra current. Most aux lights are sold as a kit including wiring and relay and switch. The way a relay works is a small coil of wire becomes a magnet when energized. This magnet pulls a switch closed turning on the main power. Since the coil does not require much power at all to energize, the factory wiring is not challenged. The other current loop is from battery or other high power terminal through a fuse and usually a manual on off switch through the relay switch contacts to the aux lights to ground. This second wire loop is the stuff that comes in the kit. You can tap into either headlight socket for coil power or find a wire at the dimmer switch. The other side of the relay coil is grounded to allow current to flow through the coil. There are three wires that go to the headlight socket, ground, low beam power and high beam power. If you pull the plug, you can determine which wire is the high beam wire. There is a lot of info on this on the web, you could search for driving light wiring or look for info on Bosch relays. Most auto relays you will find will be knockoff's of the Bosch design

[Tiny Clark]

As nomad says, use a relay and use the high beam voltage on the car to energize the relay.

 

Piece of cake. If you don't think so, maybe you should have someone else help you.

[Cougar]

Looking at my info it shows the high beam relay under the right side of the dash. A red wire supplys power to the high beams. I would tap the wire to run the relay coil. Run the other side of the coil to ground. The info also shows that fuse #4 is a 15 amp fuse that is not used. If that is so you could use it for the power to run the lights. You would have to run the wire to the lights from there. Check the main power panel under the hood for a spare relay slot you could use for this. I'm not sure if one is available or not.

[mattocs]

Thanks for the help. The kit I got does not have a relay, but i'll look around for one.

 

Thanks again

[jamal]

yeah, definitely get a relay. I tapped into the high beam circuit right at the pass. side light, because there's room and the wires are right there.

 

Here are the directions I got from a guy (vrg3) on legacycentral when my directions from hella conflicted slightly with those that I got from rallylights.com:

 

Relay pin 30 -> red wire -> ring terminal for +12v

Relay pin 87 -> blue wire -> driving lights

Relay pin 85 -> black wire -> ring terminal for ground

Relay pin 86 -> green wire -> spade terminal for switch

 

Then there's another green wire with a spade terminal on one end; this green wire connects from the other side of the switch to the high beam wire.

 

And there's a split black wire that goes from the lights to a ring terminal for ground.

 

 

You should be able to get the correct results wiring like this:

 

Red wire from relay: As Hella describes, connect it to a +12v source. Ideally this would be the alternator's post, but the positive battery terminal might be okay too.

 

Blue wire from relay: As Hella describes, connect it to the driving lights.

 

Green wire from relay: As Hella describes, connect it to the switch. Connect the other green wire from the switch to one of the headlights' high beam wires. For both headlights, these wires are red.

 

Black wire from relay: Splice it into the headlight's common wire. On the right headlight, this wire is blue with a white stripe. You can use either one.

 

Then you connect the other black wire from the lights to ground. Ideally this would be a bolt on the engine block, but the negative battery terminal would do okay instead.

 

A sidenote: I hope you've already built or bought a heavy-duty wiring harness for your stock headlights. The stock wiring severely limits their output. And if you're splicing into the wires (especially if you use those vampire-type wire taps) you risk damaging its current-carrying capability even further.

[mattocs]

I picked up an automotive relay from Radioshack...it seems like it'll be real easy. The lights I got are just some el'cheepos from Advance Auto Parts. I wanted something small and bright...and they seem that they will be good. I want to get some Hella 500s on my bumper and roof rack...but that'll be another day.