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Dual High Beam


GTS 33

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If anyone is still interested in wiring there head lights so when the high beam is on, low beam comes on aswell here is a simple way to do it.

Also See the attached file for wiring diagram and finished product.

I had a mess around with this and found this the easiest way to do this. You only need to run one extra multi-core cable if you do it right.

What I used:

*5meters of 7x1.5 multi-core cable purchased from marlows (As long as the multi-core has at least 4 wires it should be ok. All the cores will be of different colours)

*2 x 5A fuses and fuse holders

*2 x 4or5 pin 12v 30A relays and relay holders if you can get them

*8 x Insulated female blade crimps

*4 x Insulated lugs with 6mm hole

*4 x Inline cable joiners (ask an auto Sparkie, tell them what you exactly want to do)

*Black cable ties

1. Firstly disconnect the plug from the back of the left hand side headlamp. You need to join one of the cores to the high beam wire and one to the low beam wire. You'll find there are 3 wires, one being the high beam, one being the low beam and the other the ground or negative.

2. Join the wires in a way so as there is a good connection and are as neat as possible. I ran the multi-core along in front of the radiator where some of the original cables run, have a look to see and you should be able to hide it quite well. Then cable tie the cable in place.

3. The cable should then run past the right hand side head light where I put a hole in the outer sheath of the multi-core and managed to pull two cores out (this was a little bit tricky, see below for tip) so as I could join to the right hand side head light in the same way. Run the end of the cable around to the fuse box or wear ever your going to mount the relays and fuses.

4. Firstly connect the two wires from the left hand side headlight to the first relay. Connect the High beam wire to terminal 86 on the relay and connect the low beam wire to terminal 87.

5. Then do exactly the same on the second relay.

6. Run two separate wires from a good ground or negative to terminal 85 on each relay.

7. Then run a hard active straight to the fuse (fuse holders), do this on both relays.

8. Then from the fuse run a wire to terminal 30 on the relay, do this on both relays.

This probably could be done using only one relay, but I thought it would be better to use separate relays and fuse them individually. Attached is a basic wiring diagram, This is just for one side so just duplicate on the other side.

Tip: Gently make a hole in the outer sheath on the multi-core cable. Try pulling two wires through the hole. Just don’t pull the two wires used on the left hand side headlamp. When pulling them through you’ll need to wiggle the cable quite a bit. I ended up pulling them through a bit from the end that goes towards the fuse box then cutting them. You only need about 50mm.

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  • 2 weeks later...

Heh, this mod is cool :-) Looks much better now all my lights come on with high beam :-) And now I can point the high-beams further up so I can see further along the road and see what's close at the same time :-)

Oh, and you can get those in-line joiners at Dick Smith powerhouse, or I found some at Auto-1 in kensington.

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I found that the idea is really simple, ONCE you work it out in your minds eye on how it's supposed to work. But until that happened with me, it was as confusing as hell...

I'm going home to bathurst in a few minutes, so I'll borrow my old man's digi-camera, take a few happy snaps and write up a little something for you guys... After a few laps of the mount though :(

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Ok. As promised. Some pics and stuff

Anyway, as GTS 33 said, you want some 5A blade fuses (get more than 2, in case you blow them - like me), a bunch of insulated female blade crimps (just get a box of 10), a couple of those blade joiners (just get a bag of 10 from Dick Smith), 2 car horn relays, some trusty cable ties, and a couple of meters of wire. I found some 2-core wire at Dick Smith and used that instead of 4 cored wire... I find it a little more managable. Also, the relays have the terminal numbers printed on them.

On my car, behind the headlight assembly there were 3 wires. Black (ground), red (high beam), and green (low beam). My new wire was nice and simple red and black stuff. So I decided to make red low beam and black high beam (heh, the opposite of what's in the car). You car may use different colours though.

Here's how you want to wire it:

Red (high beam) -> Relay terminal 86

Green (low beam) -> Relay terminal 87

12v source -> Fuse holder -> Relay terminal 30

Ground -> Relay terminal 85

If you got 5 terminal relays (like me), make sure you cover terminal 87a with a blank crimp. You don't want any possibility of shorts.

If you look at my pic of the relay box, I found a 12v source near where those funny fuses are. You can also use a lug crimp to go directly to those 2 beefy 12v bolts on the right-side of the box.

The ground was a little more tricky. You can in theory run it to anywhere on the car body, but I couldn't find anywhere to attach it. So I ran another wire and joined it to the ground (black wire) of the left head light assembly.

Once it's wired up, here's how it's meant to work...

- High beam goes on. Low beam goes off.

- High beam sends 12v up to the relay's coil. The relay clicks closed.

- 12v goes from the power source through the closed relay terminals and out the wire to the low beam

- Low beam goes on :)

- When the high beam is turned off, the coil de-energises and the relay opens. The lights then function as normal.

Pic: blade joiner and a crimp. Notice the insulation on the crimp, and the blade + cover on the joiner. After you put the wires in the blade joiner, the blade must be fully pushed in so that the cover can close firmly. If it's not in far enough, this mod won't work (as I found out).

PIC: http://www.skylinesaustralia.com/forums/at...ntid=4981&stc=1

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Pic: The relay box. You can see 2 relays, 2 fuse holders, and lots of new wire.

Notice where the 2 fuse holders get their power from - it's a perfect fit for a blade crimp :-) The wires attached to the fuse holders are 30 amps, so be careful when crimping the ends on.

You should also be able to see that the terminals on the relay are perfect fits for the crimps as well :-) No need for relay holders :-)

That extra blade joiner you see is from sheer laziness. Basically I ran the ground from each relay to this joiner. Then after that, I only needed to join one wire to a ground point (i.e. the black wire coming out of the head lights) :-)

PIC: http://www.skylinesaustralia.com/forums/at...ntid=4986&stc=1

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