Awning LED power from leisure battery - pick holes in my plan!

[haydnw2]

Thanks all for the help so far. It's taken me long enough but I now have a feed going to some LEDs above the sliding door. The primary objective here was always to have something as unobtrusive and inconspicuous as possible. I've fitted a 30cm flat strip on a black PCB, embedded within a silicone coating. It's no more than 5mm deep, at a guess.



The cable runs behind the awning casing, with a waterproof connector near the boot in case I ever want to change the setup. Into the boot through the same hole as the solar cable, and currently terminating in the back cupboard.


It's definitely inconspicuous.


My main fear was that 30cm wouldn't be bright enough, and I'd have to replace it with a longer strip. The eBay seller won't make them longer than 30cm, and nowhere else sells properly sealed black PCB units. However, I've tested it and the light level is great, so happy days.

I now need to decide how where to feed it from. The original plan was the rear battery, but comments above suggest I should connect to the shunt rather than battery negative terminal to avoid all possibility of electrical gremlins. There's no way I'm pulling the fridge out to access the shunt, so I'm now considering taking a feed off the interior light on the RHS of the roof in the boot. Having popped out the fitting today, I see it has what look like two spade connectors on it (although they almost look joined together in my poor photo):

Has some cunning VW engineer put those there so that they can just string a set of them down each side of the vehicle instead of running a separate feed to each? And can I therefore pull from there to power my LEDs? Or am I just dreaming? I've had a scout of the forums but haven't been able to find anything. Thanks!

 

[GrumpyGranddad]

Thanks all for the help so far. It's taken me long enough but I now have a feed going to some LEDs above the sliding door. The primary objective here was always to have something as unobtrusive and inconspicuous as possible. I've fitted a 30cm flat strip on a black PCB, embedded within a silicone coating. It's no more than 5mm deep, at a guess.

View attachment 70445

The cable runs behind the awning casing, with a waterproof connector near the boot in case I ever want to change the setup. Into the boot through the same hole as the solar cable, and currently terminating in the back cupboard.
View attachment 70447

It's definitely inconspicuous.
View attachment 70446

My main fear was that 30cm wouldn't be bright enough, and I'd have to replace it with a longer strip. The eBay seller won't make them longer than 30cm, and nowhere else sells properly sealed black PCB units. However, I've tested it and the light level is great, so happy days.

I now need to decide how where to feed it from. The original plan was the rear battery, but comments above suggest I should connect to the shunt rather than battery negative terminal to avoid all possibility of electrical gremlins. There's no way I'm pulling the fridge out to access the shunt, so I'm now considering taking a feed off the interior light on the RHS of the roof in the boot. Having popped out the fitting today, I see it has what look like two spade connectors on it (although they almost look joined together in my poor photo):
View attachment 70449
Has some cunning VW engineer put those there so that they can just string a set of them down each side of the vehicle instead of running a separate feed to each? And can I therefore pull from there to power my LEDs? Or am I just dreaming? I've had a scout of the forums but haven't been able to find anything. Thanks!

I believe the feed to the light is always on (not ignition switched) so you could tap into those wires easily enough. Are you fitting an on/off switch somewhere?

 

[haydnw2]

Yes, it should be always-on via the leisure batteries, so there will be a hard switch in the cupboard followed by a wireless dimmer I had lying around - should allow easy control from the front then, but can be switched off when not on weekend trips to avoid any accidental activation or battery drain from the wireless controller (although I expect current draw to be tiny, and we do have a solar panel).

My initial instinct was to cut the red and brown wires and use a connector block to take a feed off them, but the connectors on the light fitting just look too good to be true. I ran out of light tonight, but I'll try and pop the ones above the sliding door out tomorrow and see whether they're daisy-chained together.

 

[haydnw2]

Having popped out the fitting today, I see it has what look like two spade connectors on it (although they almost look joined together in my poor photo):
View attachment 70449
Has some cunning VW engineer put those there so that they can just string a set of them down each side of the vehicle instead of running a separate feed to each? And can I therefore pull from there to power my LEDs?

Just an update in case anyone is looking in future. The spade connectors on the light fitting are indeed connected to power, with some caveats. They're not switched in line with the light, but it turns out that bridging the two terminals switches the light on (even if the physical switch remains off). So other than being able to add a second switch for the light I'm not sure it's of much use. If you connected an LED strip then it would be on all the time. You could add another switch for the LED strip, but then the cabin light will still turn on with the LED strip.

One scenario I will investigate is using them to easily add an LED strip under the back of the overhead locker. The light in the rear of our T5.1 isn't anywhere near powerful enough to see properly when you're rootling around on the parcel shelf, so some extra lighting running off the same switch wouldn't go amiss.

 

[haydnw2]

One final post in this thread. The spade connectors I originally tested were in the light fitting nearest the bench seat. When I looked at the one in the boot today it was showing 0.1V across it. When I bridged the contacts, something in the light fitting broke. I've therefore stopped my experiment here, and will now go shopping for a new fitting.

As regards the awning lights, I did cut into the cables running to the boot light fitting, and everything now works swimmingly. Thanks to everyone for the help throughout.