Thread: PROJECT 3, Driving light wiring up grade

Hi Drivesafe,

I've coupled my driving lights with the headlight upgrade using one of the two spare slots in the the four fuse box for the driving lights.

A couple of observations.

1. I fused the supply to the relay with a 30A fuse rather than fusing the supply to each of the lights after the relay.

Any issues there?

What amperage do you recommend for each of the lights?

2. 5mm wire is hard to get at my usual outlets so I used 6mm.

3. There seem to be two types of relay. One that switches between two accessories (87 and 87A) and one that send the current to two accessories (87 and 87).

4. Finding the high beam wiring under my dash was like finding a needle in a haystack so taking the wiring back to the headlight upgrade made the job easier. I found a convenient earth under the dash.

5. I used a Narva illuminated rocker switch that fitted into one of the slots after pulling out one of the unused dummy switches on the LHS of the binnacle. (I'll post a photo for Disco owners)

Hi one_iota, if your driving light globes are 100w then you will be pulling about 16 amps and for 130w you will pull about 20 amps
As the 6mm2 cable is good for 45 to 50 amps, the 30 amp fuse is fine and putting it before the relay is actually better.

Don’t fit a fuse that is close to the expected maximum current of any circuit as the fuse can some times melt but not blow as the current does not exceed the fuses limit but just heats it up.

As for finding the headlight wire under the dash, know what you mean and there is know quick way around it, except for the way you did it.

By the way, if you used a three position switch and wired the switch as shown in the diagram then if the switch is in the centre position, the driving lights will be off at all times. Switched to one side, you can operate the driving lights when you turn on your high beam or switched to the other side will operate the driving lights at any time, whether the headlights are on or off.

The first relay you have posted is a change over relay and the second is your typical headlight relay. Either will do the job with just a slight difference in wiring.

Cheers

Here are a few pictures of the roof mounted driving lights.

As a welder, I make a good fence painter so I spent more time working out ways to bend the steel tube rather that having to weld it.

The first two shots show the driving lights in place and the the driving lights removed.





To mount the lights, I first spread a towel over the roof and then the mounting bar with the 4 driving lights, is pushed over the short steel tube on one of the roof racks. ( see next picture ) The other side of the bar has a section cut away ( see last picture ) which allows it to drops down a similar piece of tube on the opposite roof rack.
Both sides are then secured with a 6mm nut and bolt.



The wiring, at this point, is just laid down the edge of the windscreen, under the back of the bonnet and plugs into an 8 way socket ( pos and neg for each driving light ).
The relays and fuses are permanently mounted under the bonnet. ( pics to come )

How do you tell if your vehicle is positive or negative switched headlights without tracing all the wiring?
Thanks

Hi CraigE, the easiest place to locate the high beam wire is at the back of the headlight and if you have a look at PROJECT 2, headlight wiring up grade, you will get an idea of what to look for.

<span style="color:red">One point of warning, do not use a test light to locate any wiring in or around a modern motor vehicle, only use a multi meter.</span>

<span style="color:blue">Test lights can trigger the air bag system and as such, could be lethal for anybody who might be anywhere near the air bag if it triggers. There have been a number of deaths in the USA caused by someone using a test light to try and locate wire.</span>

Cheers.

G'day drivesafe. Awesome projects, dude. And thanks for sharing your knowledge, tips and ideas. 8)

Just a couple of quickie's regarding the Positve wired headlight setup. :?:

1) The 2mm wire from the switch to 12V. Where do you suggest the best place to get 12V from? Battery direct, park light or via accessory like cig lighter, etc?

2) You say this diagram is for ON/OFF/ONwithH'Beam. What about a 2-position switch so it's only OFF/ONwithH'Beam. Would i just omit the wire mentioned above or..?

3) The 2mm purple wire from switch; can I 'tap' into the H'Beam via the same wire used in headlight upgrade(ie. dk blue one coming from 86 on relay A&C?

4) regarding Headlight upgrade project; "either one of original headlight plugs" - should I just cut and terminate other, or leave hanging, or..???

Thanks!

(i'm not really stupid, i just ask stupid questions 'cos i'm not very electrically-minded) ops: