Sigma EL lounge lighting

Help - away with a friend who has the above & his rear lounge strip lights are turned on with a remote key fob. The fob battery is ok & led on fob flashes when pressing buttons. Also some rear spotlights have stopped working (bulbs ok). He's not sure where his fuses are - anybody help me sort out (I'm an electrical engineer). Thanks

The fuses should be under the wooden trap door in the wardrobe, pull the draw out and the fuse bank and Truma units should be revealed, I'm assuming the EL electrics are in the same area are my last Sigma EK .
Happy holidays.
Boaby

It might depend on the year of the vehicle.

Can't remember exactly but I think it was around 2004 that the Italian suppliers of the control panel used the wrong solder on a batch of panels.

No - I'm not joking. It oxidised in damp weather and if you were one of the unlucky ones it was bad enough to cause the fob operation of the lights to fail.

If it is that, there's no permanent cure other than a replacement panel, but ours sometimes began to work again after (presumably) it all dried out again.

Implausible I know, but I was asked to take our van to Willersey (we live quite close by) for the experts to examine, so I was in at the kill, as it were!