LED interior light replacement

[Matt_J]

Hi Folks,

I’m looking to replace the interior lights in the rear of my 2018 T6 Kombi for LED strip lights (preferably surface fix to attach to a new ply ceiling near the doors), however, I’m looking for something that has on/door control/off in it so i don’t have to add in a switch or anything to achieve simple internal lights for day to day use but I can switch them off when using as a camper. So they’re as close to like for like replacement in wiring terms….

Has anyone seen/found any LED lights that i can replace them with without needing to complicate the install with rocker switches etc?

Thanks in advance all!

Matt

 

[roadtripper]

Welcome to the forum Matt.

What sort of lighting do you have currently and where is it controlled from?

The traditional arrangement for interior lighting is a +12v supply that is then either switched to nothing (off), permanent ground (on) or through a door switch to ground (doors)

The nuance comes in that the +12v feed is on a timer that cuts off usually 20 minutes after the ignition goes off to save draining the battery. This means you can't use this circuit as is for camping lights you'd want on for a long period.

Additionally some cargo area lighting doesn't have local switching, the switching is done in the cab and only 2 wires, not three, go to the light fittings.

 

[Matt_J]

Thanks @roadtripper ! Appreciate the reply!

I’m currently mid-conversion. When the ceiling ply goes in, we’re going to have rechargeable USB lights hanging from bungee loops in the ceiling (https://www.theplyguys.co.uk/product-page/suas-van-ceiling) as the main lighting for camping - we can move them around to zone the van a bit and can take them out when not in use etc. We will have a leisure battery system in for USB, USB-C and a 12V plug socket for accessories etc and a future heater.

So basically I’d like to replace the 2 x standard rocker light things that come in a T6 (with on, door control, off) with something that is surface fix and that basically does the same (just better!) for normal everyday use (getting kids in and out of the Kombi seats etc). I’m pretty happy just replacing them with something if i can find something that works - nothing i can find seems to have 3 settings on it, just a standard on/off button or a need for a switch installed too. If the only way is to put in a three setting switch and wiring into the leisure battery etc then I’m happy to have a go at that, it just seems pretty complicated (if you have a super simple explanation for it, that would be amazing, everything I’ve found seems pretty complex!)

Thanks again!

 

[roadtripper]

Do you have 3 wires at the light fittings or 2?

 

[Matt_J]

It has three wires in each fitting….two of these….

 

[roadtripper]

Cool so you have all three wires I spoke about, one will be the +12v timed supply feed, one will be the permanent ground and one will ground via the door switches (so only grounded when a door is open)



You have two options here really:

If you want to keep all three options then you wire the new light strip in with the +12v feed straight to it and then you connect the ground/0v to the centre pin of an ON-OFF-ON SPDT three position switch and the two grounds to the outer pins.

Switches like these.

The second option if it's not easy to figure out a way to mount a three way switch that your happy with is find a light strip with an on off switch built in and wire it to the +12v and the door contact circuit. That will give you most of the functionality (on with the doors off for camping) without the permanent on (which would only last 20 minutes after ignition off and you have alternative lighting anyway)

 

[Matt_J]

Ok great! So to make sure I have this right…..

Connect the +ve/live from the current plug to the live for the new light, connect the other two from the current plug to the outer pins of a rocker switch and a new earth to the centre pin of the rocker switch earthed to the chassis?

 

[Matt_J]

Sorry - the reason for checking is that I have three wires and you mention four so I want to be sure I’ve understood (which I might not have done!! Apologies!!)

 

[roadtripper]

Yes you'll need an additional 4th new wire to connect the ground from the new light fitting (not the chassis) to the centre of the switch.

What you are doing is moving the negative of the light between nothing (centre off), direct to ground via the existing wire (always on), ground via the door switch existing wire (on when doors open)

The lights are switched on the negative side, which is a little unusual as generally things are switched on the positive side.

 

[Matt_J]

Ahhhh! I see! That makes sense!! Sorry for being slow there!!

I really appreciate your help with this - I’ll give that a bash and see if I can work that through! Thanks so much! I’ll let you know how I get on!

Thanks again!

 

[roadtripper]

No problem, a diagram would have helped but I'm on my phone right now so tricky.

Plenty of helpful folks on the forum have done this before so if you get stuck or need a bit of inspiration post some pics and someone will likely chip in

 

[MarkHorrell80]

Yes you'll need an additional 4th new wire to connect the ground from the new light fitting (not the chassis) to the centre of the switch.

What you are doing is moving the negative of the light between nothing (centre off), direct to ground via the existing wire (always on), ground via the door switch existing wire (on when doors open)

The lights are switched on the negative side, which is a little unusual as generally things are switched on the positive side.

Very helpful & clear ! Had to read it a couple of times - but thanks for sharing ur knowledge. I’m buying the parts today & starting it tomorrow