12v led marker light questions.

[4String.]

Folks.

Have just finished constructing a roof rack/solar panel/accessory mount for my Transit camper and need some wiring advice.

It's made from 4"x2" aluminium angle and the rear section is fitted with five 12/24v led markers, like so:



The lights are "dual polarity", according to the instructions, and the 2 wires can be connected either way round, here's the other side, which will be facing forward:



What's the best way of wiring them up, can I "splice" one wire from each light together as a common earth and do the same with the other wires for a common live, then connect them to the rear lights on the van via a 2 core cable running through a "glanded" (is that a proper word??) hole in the roof, or is there a better way? FYI, I'm no auto electrician, the last time I did something like this I used Scotchlock connectors and lots of insulation tape .

And even though the lights don't draw much, will the extra load be a problem for the existing light circuit? (66 plate Transit Custom, presumably canbus )

And at some point in the future I might look at fitting a pair of led spot/flood/work lights onto the roof rack and wired into the reverse lights, so presumably they can be wired similarly? My drive is pitch black in winter and I have to keep the nearside of the van tight to the neighbours' wall. The existing reverse lights are woefully inadequate, hence the need for more lighting.

Much thanks.

Martyn.

 

[ajlelectronics]

Cut them short, add plugs. Then run a twin 'bus bar' from one end and connect sockets to pick up the plugs.

 

[Robotstar5]

Stick a length of self-adhesive mini trunking (other sizes available) across the width to collect all the cables and make the connections out of sight/weather. If you want really tidy, remove all the lights and spot the holes onto the back of the mini trunking so no cables will be visible.

 

[Turbo]

Not sure about adding extra lights to the van circuits, it can cause a hissy fit on some canbus systems.
If it does you can add a relay in the circuit.

As for the extra reversing light, you will likely need a relay for that if you go for one of the led light bars.
https://www.ebay.co.uk/itm/30585850...k9GRXvvzp1YbNzJq7OgWeCsvV_FRiPrwaAlgPEALw_wcB

But you will need a dash mounted switch with a tell tale light so that the extra reversing light doesn't operate during normal driving.

When you are putting a cable up to the roof use a bit of multi core to give you at least 4 wires for the marker lights and reversing light. The less holes you drill the better!

If you don't already have one fitted can I suggest fitting a reversing camera. It would fit nicely into that light pod.
I know you are a pro driver but believe me it is one of the best mods to do to a van. Makes parking and hitching up trailers a breeze.

 

[Turbo]

As for connecting the lights up my idea would be this.

Start at one side and connect the live from the first light to your live feed using solder and insulate with glue line heat shrink..

Run the live feed wire to the next light and strip off about 20mm of the outer insulation. Strip back the live of that light, wrap it around the core of the live feed and solder it together. Insulate with heat shrink.

Continue along using the same process to connect all the lights.

Repeat the process for your earth feed.

Protect all your wiring in a length of mini trunking as suggested above.

The live and earth feed wires have been stripped from the multicore wire you have feeding your roof mounted accessories. You could use 7 core trailer cable as that will give you spare cable for any future extras like your solar panels.

All this soldering, etc can be done before fitting the light pod, just leave a good length of cable to go down through the roof.

Work out where you are connecting to in order to end up at the right side of the van. My van already had a connector fitted at the rear end for connecting a trailer socket wiring harness. It already had a switched live, etc which made life easy for adding relays.

 

[hotponyshoes]

Maybe try pushing some wires into the back of a bulb holder for a temporary test to see if it messes with the canbus.

On some vans you can reprogram the ecu to accept led/extra lights.
For example, on vw, you can disable the bulb failure warnings for each individual circuit.
Or, if led was available as an option you can enable that instead. Ie, an early amarok was available with led numberplate lights so you can add extra ones to that circuit. It's only later versions that had led tail lights.
Some also have a 'body builder' socket which has its own fuses and won't cause any errors.

Or, you can add a 'canbus relay'. These trick the van into thinking only the original bulb is connected. Sometimes you can just add them in parrallel. Sometimes you need to use the wires for the original bulb just to feed the relay then feed the original bulb and the new ones from the output of the relay.

 

[Robotstar5]

......As for the extra reversing light, you will likely need a relay for that if you go for one of the led light bars.
https://www.ebay.co.uk/itm/30585850...k9GRXvvzp1YbNzJq7OgWeCsvV_FRiPrwaAlgPEALw_wcB

But you will need a dash mounted switch with a tell tale light so that the extra reversing light doesn't operate during normal driving.

You could feed the dash switch from the existing reverse lights so the extra lights could only be selected in reverse. I "automated" mine by building a AND gate circuit so it needed reverse AND sidelights before the extra lights came on, so it would only operate after dark.

 

[Trevorleach]

On the hgvs people tend to bunch all the wires together then crimp/solder then wrap each individual joint in heatshrink then once done wrap the entire lot in another much larger piece of heatshrink, problem is water always gets in might takes a few years but it always gets in.

I have started to daisy chain them with either red/blue heatshrink terminals or supaseal plugs where somehthng might have to be removed, and the top must do is leave plenty of spare wire for future repairs, nothing worse than finding out the previous guy left you zero wire to work with!

 

[hotponyshoes]

You could feed the dash switch from the existing reverse lights so the extra lights could only be selected in reverse. I "automated" mine by building a AND gate circuit so it needed reverse AND sidelights before the extra lights came on, so it would only operate after dark.

I did similar with mine, added some led lights that come on automatically to supplement the woeful reverse lights then added a switch to activate them manually to use them as work lights.
My other half has a discovery and you can use the remote control to turn the reverse lights on on that.

 

[colnerov]

Be careful with the reversing lights, construction and use regs say maximum of two.

 

[4String.]

Thanks for all the replies .

Picked up a length of mini trunking from Screwfix this morning, as per @Robotstar5 recommendation , sorted the wiring as per @Turbo recommendation , and it's all ready to bolt on:



And tested with a Milwaukee 18v battery:



Will test the lights on the van later, and as the van has a towbar fitted I'm hopeful it will be okay. I've taken the towball off as I don't have anything to tow but the next project is a dual swing-out spare wheel/storage carrier that will bolt on to the towbar.

Regarding the reverse lights, I'll probably wire some extra lights into the existing circuit. Ultimately I want to fit extra "perimeter" lights around both sides of the van but I'm thinking of wiring them in from the leisure battery and having them switched from the back of the van.

 

[4String.]

Tested the lights on the van, all is good and I'm happy with the result. No obvious problems and no warning lights on the dash, the led's just need wiring in permanently. Complete rack fitted, next job is to fit the solar panel and extra lights, then fabricate an air deflector for the front, an awning for over the side door and a 5" diameter black pvc tube on the offside for a solar shower, but they're jobs for another day...

 

[bricol]

Be careful with the reversing lights, construction and use regs say maximum of two.

And 21W each . . . And now two 5W LEDs act as reversing headlights