Caravaning

Lights and sockets

Being a caravan based on an entry level model, it hasn't got quite all the bells and whistles that some have.  I know that some 2018 models have usb charging ports in the corner spot lights and stuff.  I fancied having somewhere to charge phones and tablets on the front shelf, so did some investigating.

Sargent Electrical, who make the PSU and control panels for our Swift caravan have some schematics on their website in the support section. Looking through the Swift Group 2016 PDF, it shows that the 12v sockets are connected to the E4 connector on the PSU, with a wire that is Yellow with a white trace / strip.
The caravan handbook suggested that there are some spare outputs on fuse 9 and 10 which also might be possible to use, but no details of what connections they might be on the PSU.
Fortunately, in my efforts to get the Swift Command remote control app to program heating to work with the Truma blown air system, I'd also got a copy of the Sargent Electrical EC600 systems dealer technical guide.  This details all the pins on all the sockets on the PSU, along with their associated fuses.  Fuse 9 & 10 have their outlets on the E1 connector.

So I started investigating:

The PSU is connected to its mounting box with 4 screws, with enough slack on the wires to lift it out and see where they run.

I then took a look at the 2 connectors I was interested, and checked for voltages on the pins I hoped to tap in to on the E1 connector:

The solitary wire runs to the awning light, and pins 1-3 turn on when the light is turned on (with the light switch by the door, remote control, or on the control panel)
Unfortunately, pins 4-9 don't appear to be active at all.  I suspect that because the PSU is quite an advanced, programmable one, because there was no need in the caravans manufacturer spec to use them, they were never enabled.  This was also confirmed following an email to Sargent tech support

So plan B, the existing sockets.  They are on the red E4 connector, pins 7-9.  The schematic from sargent appears to show USB sockets being fed from these circuits, so this may be how the more expensive caravans have their circuits. The power feed for the radio goes from there too:

Eventually, I summoned up the courage to trace the wires from that connection to lower in the bundle, and then cut and connect into these circuits:

This new wire runs out from the PSU, under the battery box, between the heater and the caravan wall, along the front of the caravan, then up through the small gap that the existing 240v sockets run.  Its not an easy thing to take photos of, as there wasn't a lot of spare room.  I did try to teach myself how to feed a zip tie round existing wire, and into itself using 1 hand without being able to see!

The for the negative / ground, I matched what the rest of the caravan was using, which is White/Orange wires.  Hopefully, by matching the existing colour schemes, if anyone needs to do any work, they don't have to second guess what the wires are doing

One thing I would change if I were to do it again, is to make sure I got Berker style connectors, rather than CBE, as the chrome trim and existing sockets don't quite fit together perfectly