T5.1 Interior Light Issue - Entry & Footwell Light Relay Location?!?

[Ian Reynolds]

Hi, I have the same problem as a number of others have reported over the years with my interior cab and footwell lights no longer working.
I have checked all the fuses with my AVO meter and they are all good, so it's not fuse related.

Moving the central interior light switch to permanently on makes no difference, I've even disconnected the battery but that doesn't reset anything.
The illumination lights in the switch work do work though, so there is a side light power feed and earth to the unit. I know the earth is shared and a separate feed powers the illumination lights.

I have recently looked through the wiring diagrams and interestingly there is a mention of a "Entry and Footwell Light Relay (J348)" on page 804/1 and it says it is located "under the dash panel (centre, under the fuses)" . Pic attached from manual.

Now, I've looked and looked but I cannot see anywhere that there might be access to an area "under the fuses", I've googled and searched the WWW but cannot find any video's or articles that show how and where this might be!?!

Do any members have any clues as to how to access this under the fuses area, under the dash panel?!? From the diagram is seems there is a big relay area there.
I am aware of the engine relays under the battery, but that is located under the bonnet and not the dash.

Any info or pointers would be much appreciated!?!

Thanks
Ian

 

[rod_vw]

You have read the note that goes with those details? I don't believe that applies to your T5.1 as surely it's later than 2009.

As far I can see the control for the interior lights all come from the Body Control Module (J519 Onboard supply control unit) your lights will be the 'fade off' type which cannot be relay switched, must be solid state.

There is a complete wiring diagram available on www.cardiagn.com . That takes a bit of wading through and you may have to enter the URL manually but it's all there in the end. If you are not able to retrieve what you need from there I have the complete manual on a USB stick.

It's a bit of a shot in the dark but from a quick look at the diagrams of which there are many depending on the exact model, these lights may all have their -ve (chassis ground) fed via one commoning point buried in the loom. Check if you have continuity between the brown wire on any faulty light and the vehicle body. If not add a temporary one and see if that cures your problem.
At normal door open conditions I think you should have +12v (ish) on both the other wires one Red/Black and one Brown/Red. These supplies should both disconnect gradually at about 12 minutes from activation. One activation by opening a door and the other from operating the over-ride switch on any lamp.

 

[Ian Reynolds]

You have read the note that goes with those details? I don't believe that applies to your T5.1 as surely it's later than 2009.

As far I can see the control for the interior lights all come from the Body Control Module (J519 Onboard supply control unit) your lights will be the 'fade off' type which cannot be relay switched, must be solid state.

There is a complete wiring diagram available on www.cardiagn.com . That takes a bit of wading through and you may have to enter the URL manually but it's all there in the end. If you are not able to retrieve what you need from there I have the complete manual on a USB stick.

It's a bit of a shot in the dark but from a quick look at the diagrams of which there are many depending on the exact model, these lights may all have their -ve (chassis ground) fed via one commoning point buried in the loom. Check if you have continuity between the brown wire on any faulty light and the vehicle body. If not add a temporary one and see if that cures your problem.
At normal door open conditions I think you should have +12v (ish) on both the other wires one Red/Black and one Brown/Red. These supplies should both disconnect gradually at about 12 minutes from activation. One activation by opening a door and the other from operating the over-ride switch on any lamp.

Rod
Hi, the wiring diagrams I've been looking through have come from the above link, I've attached the page I found the relay on! I think it's for a 2012 Transporter/California but who knows!
I'll go and do the earth check and add a new temp earth wire and live check next and see if that points anywhere. If no live then the J519 unit seems the culprit. I see https://motortronics.co.uk/ can test and repair them, so maybe that's the solution.
Thanks
Ian

 

[rod_vw]

Rod
Hi, the wiring diagrams I've been looking through have come from the above link, I've attached the page I found the relay on! I think it's for a 2012 Transporter/California but who knows!
I'll go and do the earth check and add a new temp earth wire and live check next and see if that points anywhere. If no live then the J519 unit seems the culprit. I see https://motortronics.co.uk/ can test and repair them, so maybe that's the solution.
Thanks
Ian

View attachment 99876

Hi Ian,
The fuse box location that you showed in a clip above has a note number 2, if you are able to read that note it says up to 2009 only.
I wouldn't rely too much on the page date, that is the issue date of that particular document.

 

[Ian Reynolds]

I thought I'd post a reply i case it helps anyone!
After a lot of research and nearly buying a new BCM, I found there are 3 fuses involved, 1 feed in and 2 output feeds, and yes, when I found both the output fuses 1 had blown - DOH!!
Despite me testing every fuse in situ in the fuse box, somehow there was a very small one lurking that had blown - so all fixed ;o))

 

[KGCali]

I thought I'd post a reply i case it helps anyone!
After a lot of research and nearly buying a new BCM, I found there are 3 fuses involved, 1 feed in and 2 output feeds, and yes, when I found both the output fuses 1 had blown - DOH!!
Despite me testing every fuse in situ in the fuse box, somehow there was a very small one lurking that had blown - so all fixed ;o))

Glad you got it sorted!
Where were the fuses located?

 

[Ian Reynolds]

The 3 fuses involved were as follows:
- Fuse 7 on fuse holder B
- Fuse 17 on fuse holder C
- Fuse 24 on fuse holder C

Fuse holders B and C are the ones in the centre lower dash on a T5.1, by the gear lever.

Hope that helps anyone!

 

[KGCali]

The 3 fuses involved were as follows:
- Fuse 7 on fuse holder B
- Fuse 17 on fuse holder C
- Fuse 24 on fuse holder C

Fuse holders B and C are the ones in the centre lower dash on a T5.1, by the gear lever.

Hope that helps anyone!

Found them on my fuse list, thanks.

Fuse holder B (Upper)
7. (15A) Multifunction control module1 (interior lamp)
Fuse holder C (Lower)
17. (7.5A) Onboard supply control unit -J519- (T73/66) 30 1) -1) 30G 2) Interior lights and compartment lights 2)

24. (7.5A) Left centre reading light -W39- 30G- Right centre reading light -W40- – Rear left reading light -W11- – Rear right reading light -W12- – Left interior light -W16– Right interior light -W17- – Rear left interior light -W47- -Rear right interior light -W48-