Gents,
Need some advice.
During a recent service, the dealer told me that my rear fogs weren't working and I needed a software update as I'd had a tow bar and tow bar electrics fitted by a third party.

I thought this odd, as they were working just fine at the previous MOT well after the electrics were fitted.

Anyway, I've had a look today and I can find no obvious problem.
The fog light fuses (32 and 38) behind glove box are fine.
The fuses for tow bar wiring (plug in harness) are all fine.
The fog lamp bulbs are ok.

Any ideas?!
Is there a relay for the rear fogs?


Many thanks in advance.

Any advice would be most welcome!

To provide some form of reply, have you checked for breaks in the wires or connections?
Failing that the fog light button itself? Do the bulbs just look ok, or have you tested them?
Obvious ones really, but I guess from the lack of replies its going to be something like that.
Good luck. MY11 RRS HSE
Buck Blue

Thanks for the feedback.

To be clear, there are no fault lights on dash when I switch lamps on- pointing to blown bulb/ bulbs etc.
The fog lamp indications on dash functions normally - as if all fog lamps are working and illuminated but when I get out and inspect, only the front fog lamps are on.

I have checked all fuses that i can find with multimeter ( in fuse box behind glovebox)
Did not continuity check bulb as they looked absolutely fine when visually inspected.
I have not traced/ continuity checked wiring through yet, as fuses are all fine although BOTH rear fogs have stopped working pointing to some kind of common failure but not a short.

I was hoping that you guys may know of a common problem or point me towards a relay etc, which may cause both lamps to stop working.

If not, I'd be glad to hear suggestions from anyone who has had a similar problem or may be able to point me in the right direction.

As a side note, I have an MOT coming up next week and would hate to have to send the car into the Stealer to get this resolved in time....

Gents,
A quick update- spent some time unplugging connectors behind rear lights and tow bar electrics and spraying everything with WD40.

Rear fog lights now working fine

Looks like there's no need for the dealer to do a 'software update' after all
Why do they talk such ?

£££££££££'s

Aha!!!!!!!!!!!!!!!

I've just experienced this EXACT problem on my 58 plate RRS TDV8....strangely I checked whilst the fault was apparent and the car rear fogs operated with the caravan connected and didn't operate when the caravan was disconnected, which is exactly the reverse of what should happen!!!!

Fortunately the after-market wiring harness fitted to it was still under warranty so a quick call to the fitting company resulted in one of their technicians appearing at my house yesterday.

After checking the wiring (it had recently been in to the JLR Main Dealer in Coventry for service - they were the ones who spotted the failed fog lamps and I wasn't sure if they had done something) he disassembled the 13-pin socket on the rear of the car.

Interestingly there is no relay (which is what I originally thought had gone faulty)...Apparently on my model year the rear fogs are disabled by a small mechanical switch inside the socket which is operated when the caravan plug is inserted and this switch had stuck in the open position....a little jiggery-pokery and a squirt of the magic WD*0 solved the issue.

First time I have been able to post a proper response to a problem post...well chuffed!!!

Great post,

i fitted a retro trailer socket adaptor to my 2010 TDV8 and the rear fogs lights stopped working. After looking at bulbs and fuses i came across this post.

i removed trailer socket adaptor and fogs working again.

many thanks