Replacing OEM LEDs in Cargo area using original wiring loom

[Atwcm]

Hello electrical geniuses

I'm converting a T6.1 panel van so at the moment have the two OEM LED ceiling lights with no override switch at the lights.
I've read the threads I can find regarding this and see that it can be set up whereby the cargo area lights can be wired via a three way toggle switch (located near the sliding door in my case) so that;
Position 1 - standard set up - lights fed from starter battery - will come on when doors are opened and will turn off on timer (or when the engine is started)
Position 2 - lights permanently off
Position 3 - lights fed from leisure battery & permanently on

I'm thinking that Position 1 would be a case of tapping into the existing loom 12v + supply wire
Position 2 - no connections to be made
Position 3 - fed from the 12v + supply fuse board connected to the leisure battery and negative going back to my negative busbar

Just wanted to confirm that this is correct and that by adding additional lights to the existing loom circuit (for the timed/door operated Position 1 option) I won't be overloading the circuit
Specifically I'll be removing the two original LEDs and installing six 2.5W recessed ceiling lights (as per the amazon link below) and operating with the switch linked below that

Lights https://www.amazon.co.uk/dp/B09D9BGXHN?psc=1&ref=ppx_yo2ov_dt_b_product_details

Switch https://www.amazon.co.uk/gp/product/B07V35LB7M/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I won't be making any of this live until an auto electrician has run his eyes & multi-meter over my work

Any advice much appreciated

Cheers

 

[Dellmassive]

Some. Background info here.....

LED Interior Cargo Lights - How I Done It.

LED rear interior lights - How i done it. so a few have asked, so i though i would just list it here as a post so i could refer back to it in the future. The lights were purchased from The T6F shop over here > We were planning to do the carpeting at around the same time, but for the purpose...

www.t6forum.com

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[Deaky]

The courtesy lights are switched on the -ve side. Probably easier to run them permanently from the leisure battery and use the original -ve to switch them with the doors then add another permanent -ve for constant on

 

[Atwcm]

Thank you Dellmassive and Deaky.
So my notion of just using a three way rocker switch is a no go?
Sounds like a relay is needed and also a diode to prevent leakage back from leisure battery to starter battery?
But Ok on replacing the additional two lights with six 2.5w lights with regard to not overloading the OEM loom?
Cheers

 

[roadtripper]

You shouldn't need a diode, your starter and leisure batteries will share a common ground (the chassis) and that's what the door switch switches to.

If you wanted to use a 3 way switch then run +12v from the leisure battery to the lights and then the ground through the 3 way switch. Leave one way unconnected for off, wire one to ground (switch lights on permanently) and wire the final one to the door switch (switch lights on doors)

This is what the OEM 3 way lights do, it's just the +12v comes from a BCM times feed that cuts off to save power.

 

[Atwcm]

Thanks for that Roadtripper.
So just to clarify when you say "and wire the final one to the door switch (switch lights on doors)" that would be running one of the original wires going to the two removed OEM Led lights through the switch to give a door operated and timed ON state?
Thanks

 

[roadtripper]

There wouldn't be any timed on state because you wouldn't use the timed BCM +12v feed.

If you are wanting to feed the lights from a different source and you want to move the lights anyway might it not be easier to leave the OEM ones as is for door triggered lights and add the new lights with basic on off from the leisure battery?

 

[Atwcm]

Yes easier for sure (for my skill level) but I just imagined a clever solution might exist whereby I could get rid of the existing light holes (and the horrible white light they emit) and have six evenly spaced new lights with the functionality of timed/door operated light and convenience of on/off on demand.
Seems like that might be a stretch though.

 

[Atwcm]

In my head it seemed like the six new lights could be wired into two independent circuits.
First one is identical to the set up as it is now - on with the doors open and off on the timer.
Then click though the middle switch position where nothing is connected and therefore lights stay off and finally the third switch position is linked to a second circuit fed by the leisure battery.
I thought maybe that's what Dellmassive was suggesting with diodes to keep the two circuits isolated from each other so that starter battery and leisure battery weren't linked through the lights.

 

[roadtripper]

So you should be able to do that with a double pole 3 way on-off-on latching switch likes this:

On-Off-On Large Rectangle Rocker Switch DPDT

Rectangle rocker switch with DPDT contacts suitable for applications where a higher rated switch is required.On-off-on actionDPDT contacts6.3mm quick connect terminals28 x 21.5mm panel cut-outMaximum current: 16AMaximum voltage: 250VACDimensions: 35 x 31.2 x 25mm (Height x Length x Width)

www.switchelectronics.co.uk

Each side will switch one wire to the lights so effectively it will move them from the standard circuit to the leisure circuit but never have them connected to both.

So the lights would be wired to the middle pair of contacts.

Then for the courtesy position "I" you would wire the positive contact that end to the BCM +12v feed that currently goes direct to the lights and the negative contact to the door switch feed that currently goes directly to the lights.

And for the camping position "II" you would wire the positive contact that end to a fused feed from your leisure system and the negative contact to a permanent ground.

If you are fitting low wattage lights you shouldn't have any issue with the current capacity of the existing loom.

If you're not confident then do consider getting some help as both the feeds to the existing lights actually come from the van electronics, the door switch isn't purely mechanical these days it's electronically controlled to do the dimming fade out. The electronics are reasonably robust but still would not be a good idea to short them or misconnect them.

 

[Deaky]

Connect them like this.

 

[Atwcm]

That's great Roadtripper and Deaky.
I ordered this switch in my haste before posting the question yesterday but I think its basically what you suggest.

Taiss/2Pcs Waterproof Rocker Toggle Switch Black 16A 250V 20A 125V AC 6 Pins 3 Position ON/Off/ON DPST KCD4-203N-BK https://amzn.eu/d/6DqPEhe

I will get another pair of (qualified) eyes on this before making it live but can lay the groundwork in the meantime.
As it seems to be something that's unconventional I'm curious how others resolve this.
If the existing lights are left in unaltered (in a panel van with no light override switch as standard) and an additional set of camper lights are added to a leisure battery circuit how does everyone counter the scenario where person A gets up for a pee in the night and person B is left lit up like a football pitch by the timer controlled white Leds until they return?

 

[roadtripper]

If folks leave it as two separate circuits they will tend to turn off the courtesy lights while camping (by adding a switch if needed), but leave them on during the week when the van is being a van.

Or they will do one of the wiring techniques discussed if they want something a little more automated.

It's not unconventional, there are 10 pages of different approaches and ideas discussed under @Dellmassive thread.

 

[Atwcm]

Thanks for pointing that out.
I'd read the Dellmassive thread and didn't even notice it continued past page 1.
Cheers

 

[Howzat]

The courtesy lights are switched on the -ve side. Probably easier to run them permanently from the leisure battery and use the original -ve to switch them with the doors then add another permanent -ve for constant on

I did exactly this but added 2 switches so I could switch each half of the cargo area.

 

[Atwcm]

I did exactly this but added 2 switches so I could switch each half of the cargo area.

Good idea - the switch I ordered came as a pack of two so might as well follow suit and do the same. Thanks

 

[Dellmassive]

Remember that the switch method is still subject to the BCM timer .... If not using a separate POS feed from a leisure battery.(Ie standard setup using starter battery)

15mins for standard rear lights, and 30mins for LED rear lights .. as the timer is on the 12v POS wire .

To reset the timer you need to open/close a door or lock/unlock via remote fob.

 

[Deaky]

Remember that the switch method is still subject to the BCM timer ....

15mins for standard rear lights, and 30mins for LED rear lights .. as the timer is on the 12v POS wire .

To reset the timer you need to open/close a door or lock/unlock via remote fob.

Not if you use +12v from the leisure battery as my drawing.

 

[Howzat]

If the existing lights are left in unaltered (in a panel van with no light override switch as standard) and an additional set of camper lights are added to a leisure battery circuit how does everyone counter the scenario where person A gets up for a pee in the night and person B is left lit up like a football pitch by the timer controlled white Leds until they return?

My OEM lights are switched on a T6 so are they not on the 6.1? If that is the case just remove the bulbs from the OEM lights and use only your LED's, then when going bo-bo's just flick your new switches to the off position, or just leave the sliding door end switched to door sensor and the back end (where your head rests) to off, which is what I do. Then you're not blinded by the lights overhead.

 

[Dellmassive]

Not if you use +12v from the leisure battery as my drawing.

Yep, agreed.

I've edited above to add that the timer only applies to the starter battery POS feed.

And not if you use a separate leisure battery feed.