LED Interior Cargo Lights - How I Done It.

Dellmassive

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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 >

upload_2018-8-29_18-18-55.png

We were planning to do the carpeting at around the same time, but for the purpose of this thread ill leave the carpeting bit out.

first thing to do was to remove the existing roof lining by popping out the grey plastic hex head pop studs, they all unscrewed easily, the center support bar popped out with a plastic trim tool... no problems so far....


32.jpg

The existing OEM LED light unclipped easily reveling the loom and connectors . . .

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once the panels were out we layed them out on the floor and used a string line to work out where we wanted the new lights and what spacing we were going to have . . . . .

34.jpg


because we had already carpeted the panels, drilling into them was going to be a challenge ( the drill bit snagging the carpet) but and old car audio ICE trick was to put the drill in reverse and burn through the carpet, once burned through you could go through normally. . . . we drilled holes for the cable entry to the back of the panel and poked the wires through. . . . .

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next up was to mount the lights, we used the small self tapping screws that comes with the kit to screw into the backing board, then fitted the covers over the screw fixings . . . .



36.jpg

next task was cable management, we cut off the small two pin connectors and layed out the cables to roughly where we needed them. We used white gaffer tape to tape down the cables to stop them ratteling etc . . . . we bought the excess cable through the OEM light fitting hole.....we decided to keep the OEM LED lights as dummy units, the also helped out as a good cable way and access panel of sorts to get to the connections . . . .


37.jpg

now the new LEDs were fitted we could refit the panels in the back of the van . . . we pulled the existing loom and original connectors out the hole where the old light was. . . . . .

using a multi-meter we measured the BCM 0v ground wire and the BCM timed 12v+ wire (when the rear door was open) and joined them with crimp terminals to the OEM loom . . . leaving the original connector on the end.


***************************************************************************************
Factory Non-LED 3 wire setup:

(brown) - earth point left a-pilar
(brown/red) - connection 1 main harness (BCM switched neg 0v)
(red/black) - positive connection 1 main harness (BCM timed +12v) ( 7.5A fuse 24 holder C)
****************************************************************************************

Factory LED 2 wire setup:

(brown/red) - connection 1 main harness (BCM switched neg)
(red/black) - positive connection 1 main harness (BCM timed +12v)( 7.5A fuse 19 holder C)

****************************************************************************************
BCM rear light TIMER :

credit: @JCElec

You can change the time by changing module 09 chanal 038. standard value is: 21 (10.5 minutes) en you can change it to 254 (127 minutes). it's multiplying whit 30 sec.

@mmi Excellent info. Thanks. Seems to match with my observations in thread Led Rear Interior Lights - How I Done It.
- channel 38 in my van has value of 121 - and indeed I had observed the lights (obviously the new setting came with factory LEDs in cargo space) stay on for 60 mins.

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38.jpg

once all back in the van we tested it all making sure that the new LEDs didnt flicker and also went off when the van doors were closed/van locked etc.


FYI: This van had the factory OEM REAR LED pack option so already had the rear LED light modules with no-rocker switch. also the loom had only 2 wires. It also looks like you will get an extended ON time of around 60mins before the lights shut off.

If your van has the standard rear filament lights you would most likely have a rocker switch on the lamp unit and 3 wires in the loom. (0v ground perm, 0v BCM switched, BCM timed +12v perm) The BCM shut off time will be around the 10 - 20 mins mark.


for people looking to have a override switch for say a camper etc then a fused +12v feed wire would be used to feed the lights in addition to the BCM feed. A blocking diode may be needed on that feed wire.

If your switched override feed was coming from the AUX isolated battery feed in conjunction with the BCM feed (from the starter battery) i would defiantly fit a blocking diode to stop any back flow of current from the AUX and STARTer battery.

some people just totaly disregard the BCM +12v feed and just use the new +12v AUX feed, though a warning on this point is that if the lights were left on all night there is a chance of discharging the feed battery to a dangerously low level causing possible damage. . . . . . low voltage cut-out are available to prevent this from happening.

A relay can also be used to shunt the lights from BCM van control over to Leisure battery for extended light on times for camper-van setups and the like.

Hope that answers some questions I've had. =]

More info over here > Dellmassive`s -- "how I Done It" -- Thread

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Could a relay of some sort be used instead of a blocking diode? Trying to work something similar out myself
 
Could a relay of some sort be used instead of a blocking diode? Trying to work something similar out myself

yes it could, . . . . as @Deaky mentioned about the circuit is -ve switched with a timed +12v feed

so if you want to mix the starter battery feed with the AUX battery feed (for longer than the 60min/20min BCM timer ) you would need to isolate the two battery feeds from each other, blocking diodes would work as would a DPDT relay.

What exactly did you have in mind? . . . ie - how do you want it to work?
 
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yes it could, . . . . as @Deaky mentioned about the circuit is -ve switched with a permanent +12v feed

so if you want to mix the starter battery feed with the AUX battery feed (for longer than the 60min BCM timer on mine) you would need to isolate the two battery feeds from each other, blocking diodes would work as would a DPDT relay.

What exactly did you have in mind? . . . ie - how do you want it to work?
Sorry to hijack your thread! I basically want to connect an LED strip light into the trim panel above my slider. I want it to act like the courtesy light that’s there currently does but also want a separate switch that is fed from my leisure battery so that I can have it constantly on when needed and avoid the BCM timeout. Cant quite get my head around the wiring of that setup
 
@xpfloyd

You got it right there...

You would need to use a 12v dpdt relay to shunt your new striplight power and ground connections over to your leisure battery feeds.

That way normally operation would be BCM controlled timer. Then when you flick your switch the relay contacts will change over to connect the light to the aux battery feed leaving the bcm feeds unaffected.

its a bit rough, but this kinda thing. using a rocker switch, fuse and a dpdt relay.

51.jpg

and a relay like this one . . .

52 dpdt-relay.png

a few option here>

https://www.amazon.co.uk/Sonline-HH...qid=1535575096&sr=8-1&keywords=12v+dpdt+relay

https://www.amazon.co.uk/SODIAL-JQX...qid=1535575096&sr=8-2&keywords=12v+dpdt+relay

https://www.amazon.co.uk/Spiratroni...id=1535575096&sr=8-12&keywords=12v+dpdt+relay
 
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could you just ditch the existing positive wire and replace with a positive from your leisure battery, as long as your leisure batt is grounded to chassis it will work, only down side is leaving a light on will flatten your leisure battery

It’s worth noting I have found that generally the timer relay for interior lights is a lot less than 60 mins, I would say 10-20 mins is more typical, I’m guessing it may be longer either because you have facTory LED lights or the tolerance on the relays is not accurate (unlikely I think) and of course there’s always the possibility we are both just really crap at estimating time :laugh:
 
@xpfloyd

You got it right there...

You would need to use a 12v dpdt relay to shunt your new striplight power and ground connections over to your leisure battery feeds.

That way normally operation would be BCM controlled timer. Then when you flick your switch the relay contacts will change over to connect the light to the aux battery feed leaving the bcm feeds unaffected.

its a bit rough, but this kinda thing. using a rocker switch, fuse and a dpdt relay.

View attachment 27591

and a relay like this one . . .

View attachment 27592

a few option here>

https://www.amazon.co.uk/Sonline-HH...qid=1535575096&sr=8-1&keywords=12v+dpdt+relay

https://www.amazon.co.uk/SODIAL-JQX...qid=1535575096&sr=8-2&keywords=12v+dpdt+relay

https://www.amazon.co.uk/Spiratroni...id=1535575096&sr=8-12&keywords=12v+dpdt+relay
Thank You!!
 
could you just ditch the existing positive wire and replace with a positive from your leisure battery, as long as your leisure batt is grounded to chassis it will work, only down side is leaving a light on will flatten your leisure battery

Im sure you could, that would in effect draw power from the AUX battery instead of the starter battery . . . .

It’s worth noting I have found that generally the timer relay for interior lights is a lot less than 60 mins, I would say 10-20 mins is more typical, I’m guessing it may be longer either because you have facTory LED lights or the tolerance on the relays is not accurate (unlikely I think) and of course there’s always the possibility we are both just really crap at estimating time :laugh:

Agreed, i think what is happening here is that the original factory fit filament bulbs and 3 wire loom (plus rocker switch on lamp) have a shutoff timer of between 10-20 mins as you say . . . . i had the same on my T5.1.

But. . . . . . .

It looks like if you have the factory fit LED units, then you get a factory LED lamp units, only a 2 wire loom and a 60 min shut off timer.

seems VW are giving you more time due to lower power consumption of the LED lamp units.

ill edit the above to reflect the differences.
 
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The timer is on the positive supply, the negatives are one permanent and one switched from BCM so an aux positive would work ??
Not sure if it’s different with your factory LED two wire setup ??
 
The timer is on the positive supply, the negatives are one permanent and one switched from BCM so an aux positive would work ??


Not sure if it’s different with your factory LED two wire setup ??

i didnt take any meter readings at the time . . . . ( except which was pos and neg when the lights were on)


FYI - my loom 2 wire colours (factory fit interior LED lights option) are:

red cable/black tracer (assumed BCM timed+12v +ve)
brown cable/red tracer (assumed BMC switched 0v -ve)

65.jpg
 
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It’s worth noting I have found that generally the timer relay for interior lights is a lot less than 60 mins, I would say 10-20 mins is more typical, I’m guessing it may be longer either because you have facTory LED lights or the tolerance on the relays is not accurate (unlikely I think) and of course there’s always the possibility we are both just really crap at estimating time :laugh:
In the vans with "regular" lights the delay indeed is way less. The timeout in a van with the LEDs is significantly longer. And, seems to be quite consistent - can leave lights on and come back after 59 minutes to see lights go off :). Initially thought they never switch off.
 
The switched negative does come from the dash but think of it as a door switched negative (like times of old) I believe it’s only routed through the dash to give you the extra few seconds of light after shutting the door and to allow the lights to dim off rather than straight off
If you manually switch the cargo lights on it flips from the door switch negative to a permanent negative and the BCM negative control is removed so it has to shutdown the positive supply to force all lights off and stop a flat batt if accidentally left on
 
The switched negative does come from the dash but think of it as a door switched negative (like times of old) I believe it’s only routed through the dash to give you the extra few seconds of light after shutting the door and to allow the lights to dim off rather than straight off
If you manually switch the cargo lights on it flips from the door switch negative to a permanent negative and the BCM negative control is removed so it has to shutdown the positive supply to force all lights off and stop a flat batt if accidentally left on

That does make sense on the 3 wire setup i agree.... so i thought i would dig out a schematic.


This wiring pic shows the 3wires and as Deaky said, it shows:

br - (brown) - 639 earth point left a-pilar
br/rt - (brown/red) - B533 connection 1 main harness (BCM switched neg) connects to B129 to B264 to A144 to T73a/4 (J519)
rt/sw - (red/black) - B250 positive connection 1 main harness (BCM timed +12v) ( 7.5A fuse 24 holder C) to B323 to T73a/66 to (J519)

So it looks like the BCM (J519) is ultimately controlling the (BCM switched -ve)(T73a/66) side and also the (Timer switched +ve)(T73a/4 (J519))

from what i can see on Elsawin.

68.JPG



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here a snapshot from a later van with LEDS, but my German isn't that good. Its seems that the +ve supply and -ve ground are from B533 & B250 (translates to connection in roof loom)

again we have a similar setup,

br/rt - (brown/red) - B533 connection 1 main harness (BCM switched neg) connects to B129 to B264 to A144 to T73a/4 (J519)
rt/sw - (red/black) - B250 positive connection 1 main harness (BCM timed +12v)( 7.5A fuse 19 holder C) to B323 to T73a/65 to (J519)

So it looks like the BCM (J519) is ultimately controlling the (BCM switched -ve) side and also the (Timer switched +ve)

from what i can see on Elsawin.


67.JPG


so unless im reading it wrong The BCM deals with both the switched +ve and -ve and both old and new versions on the circuit. I suppose its also monitoring the circuit for bulb defects and faults etc.

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Also regarding the BCM timed lights, here is a clip showing a relay under the dash by the BCM, its unconfirmed yet whether its fitted to our van.

2a - Interior light relay -J602- (646)



Capture.JPG


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Additional info provided by @mmi

Slightly diverting from the original post but thought might be useful add here for future queries/upgrades.

As @Dellmassive mentioned new LED lights in rear roof lining are connected with 2 wires.
led_connector_a-jpg.27302

And indeed the LEDs do not come with a switch so they stay always on (up to 60 minutes) when a door is open. Current draw is about 0.2 Amps (@12.2V). I think that light output is definitely satisfactory. The color of the light is approx. medium white (personal opinion, compared with so called warm white and cold white LEDs).

The frame is 137 x 67 mm. The opening in the roof is 129 x 54mm. The light requires 17 mm of depth (from the roof surface). It has three bars of light (yellowish bars in the picture).
led_light_top_a-jpg.27303


The light has a product code 7E0 947 123 A. The connector on van side has a code 1T0972703. Can’t confirm if the LED would be a plug and play with the wiring of an “old”…
led_prod_nr_a-jpg.27304


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It looks to me like the seller has put the red and blue crimp terminals on the LEDs to indeicate which lead is +12v and 0v.

you can test this by touching them on the battery briefly, they will light if that is correct.

i would not cut off your existing connector as you may need it in future. . . . .

you can connect all the reds and blues together if you wish . . . . hopefully no more than 6 or 8 lights all in?


if you have the 3 wire loom then you have this:

***********************************************
br - (brown) - 639 earth point left a-pilar
br/rt - (brown/red) - B533 connection 1 main harness (BCM switched neg) connects to B129 to B264 to A144 to T73a/4 (J519)
rt/sw - (red/black) - B250 positive connection 1 main harness ( 7.5A fuse 24 holder C) to B323 to T73a/66 to (J519)
****************************************************


if you connect your LEDs Blue to the - brown/red (BCM switched 0v)

if you connect your LEDs Red to the - red/black (BMC timed +12v)


This will give you the same as the existing lights in the rear, ie power when door opened and will stay on till the time-out expires and will switch off.



see this thread for more details :

Led Rear Interior Lights - How I Done It.




.

Dellmassive`s -- "how I Done It" -- Thread

.
 
It looks to me like the seller has put the red and blue crimp terminals on the LEDs to indeicate which lead is +12v and 0v.

you can test this by touching them on the battery briefly, they will light if that is correct.

i would not cut off your existing connector as you may need it in future. . . . .

you can connect all the reds and blues together if you wish . . . . hopefully no more than 6 or 8 lights all in?


if you have the 3 wire loom then you have this:

***********************************************
br - (brown) - 639 earth point left a-pilar
br/rt - (brown/red) - B533 connection 1 main harness (BCM switched neg) connects to B129 to B264 to A144 to T73a/4 (J519)
rt/sw - (red/black) - B250 positive connection 1 main harness ( 7.5A fuse 24 holder C) to B323 to T73a/66 to (J519)
****************************************************


if you connect your LEDs Blue to the - brown/red (BCM switched 0v)

if you connect your LEDs Red to the - red/black (BMC timed +12v)


This will give you the same as the existing lights in the rear, ie power when door opened and will stay on till the time-out expires and will switch off.



see this thread for more details :

Led Rear Interior Lights - How I Done It.




.

Dellmassive`s -- "how I Done It" -- Thread

.
So am i to break into a wire ? If so where .? If im not to cut off the connector to the interior light how do i get a connection to make the lights work?
Also im not very aware of where each pillar is or what its called A pillar B pillar ? I ve no idea which is which ? Do i have to go in one of them to cut a wire to make o connection.
 
@Mickymiff 12v is just as dangerous as 240v. If you’re really this unsure of connecting them up then if I were you I’d get an auto electrician to hook them up for you.
 
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