Just failed MOT on number plate bulbs not working. Read an article by MONGOOSE on same subject, and apparently
they are not fused but operate through a FET!! Tailgate working perfectly. This "FET" resides in the passenger
footwell. How do I recognise it? Is it a replaceable item like a good old fashioned fuse. If not, can I wire the
numberplate lights up some other way? 2013 Dynamic Santorini black
2011 XS Lago grey
2007 HLS Stornoway grey
sometimes towing an Elldis AVANTE 574.

The exterior lighting uses FETs rather than fuses in order to enable detection of failed bulbs. (Although whether the FL2 uses such information I don't know - I've never seen a failed bulb warning, but then I don't think I've yet had a bulb fail!)

The FETs are not replaceable in the same way as fuses - they are inside what's variously referred as the Central Juction Box / Body Control Module / footwell fuse box. Assuming it is the FET at fault it can probably be replaced by a competent electrical engineer, but the problem may be elsewhere. I'd first check all the wiring and connectors.

It would be possible to wire up the lights some other way (e.g. relay off the tail lights) but better to fix them properly if you can.

I had to sort out a boot lock in July and the new switch came with the number plate loom and bulbs. So you do have bulbs that may have blown and/or the loom connectors may be goosed of course but I guess that's all been checked.

As for a fuse or even a FET:

http://www.freel2.com/forum/post108539.html FL2 MY10 TD4 GS traded in at 2 years
FL2 MY13 TD4 GS Current

pab wrote:

The exterior lighting uses FETs rather than fuses in order to enable detection of failed bulbs. (Although whether the FL2 uses such information I don't know - I've never seen a failed bulb warning, but then I don't think I've yet had a bulb fail!)

My LH Headlight bulb blew a month ago and no messages so it seems like a lot of hot air and no action.  FL2 MY10 TD4 GS traded in at 2 years
FL2 MY13 TD4 GS Current

The FET will shut down on a fault condition, change the lamps and they may well come back on, if there is a fault somewhere the FET will not start, it will sit there until the fault is cleared, effectively a self resetting fuse unusual for them to go faulty, not impossible though.

pab wrote:

The exterior lighting uses FETs rather than fuses in order to enable detection of failed bulbs. (Although whether the FL2 uses such information I don't know - I've never seen a failed bulb warning, but then I don't think I've yet had a bulb fail!)

The FETs are not replaceable in the same way as fuses - they are inside what's variously referred as the Central Juction Box / Body Control Module / footwell fuse box. Assuming it is the FET at fault it can probably be replaced by a competent electrical engineer, but the problem may be elsewhere. I'd first check all the wiring and connectors.

It would be possible to wire up the lights some other way (e.g. relay off the tail lights) but better to fix them properly if you can.

Thanks for all your answers. At the moment I have got the boot to bits figuring out how to wire the
number plate to the rear side light somehow. Think I've cracked it! But now another problem, I have
(I think) blown the (fuse??) for the rear nearside sidelight. The bulb is perfect, the earth and the live are very
close to each other!
So........where's that fuse??  2013 Dynamic Santorini black
2011 XS Lago grey
2007 HLS Stornoway grey
sometimes towing an Elldis AVANTE 574.

Um, same answer I'm afraid - no fuse, it's a FET in the CJB!

If you've just wired the plate lights to the sidelight the CJB may be registering an unexpectedly high load and may have disabled the light as a result?

Thanks Pab. I think I'll get myself an old classic!  2013 Dynamic Santorini black
2011 XS Lago grey
2007 HLS Stornoway grey
sometimes towing an Elldis AVANTE 574.

Thanks Pab. I think I'll get myself an old classic!

Young Bimbo may be more fun.  FL2 MY10 TD4 GS traded in at 2 years
FL2 MY13 TD4 GS Current

Never thought of that!!  2013 Dynamic Santorini black
2011 XS Lago grey
2007 HLS Stornoway grey
sometimes towing an Elldis AVANTE 574.

The sad bit is the car (CJB) knows that either the bulb has blown (open circuit) or that there is water in the bulb holder (short circuit), It knows, but doesn't bother to tell you, plug in a diagnostic unit and it's there in plain English.

Surely as a premium product it is not beyond the ability of LR engineers to put a text message on the screen saying something like "number plate lamp missing" - my 2003 Skoda Octavia had the facility. Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner

I recently had a similar problem occur when I replaced a front sidelight bulb with the lights turned on, I put the new bulb in and it failed to light.

The FET's have a built-in overload circuit and if an output is shorted it will shut down and remain so until reset, since they are wired to a permanent live feed as well as the switched connection, the reset is made by removing power to the CJB by disconnecting the battery, ( or fuse 17, 60 Amp in the battery junction box.)

Worked for me