TD5 lighting fault.

The missus has just called me, says that the headlights have gone off.

When she puts the switch to headlights, all the lights go off (sidelights, headlights, panel lights). When she uses the side light position it still works (side lights, panel lights on)

Is that going to be the switch?

Could be a faulty switch, but also check the main lighting 20A fuse under the bonnet (some people use engine compartment when you try and google it!).

I spent ages checking switches, wiring and interior fuses for it only to be that!

sorry, I meant 30A! and I think it might be green!

https://www.landroverworkshop.com/electrics/defender-2002my/head-side-and-tail-lamps

Here's some other info in case it's not that!

I assume this is a TD5 Defender we're talking about, so the fuse is likely to be in the bulkhead fuse box, just ahead of the gear levers.
Does anything work when you switch it to main beam with the other stalk? If so, then that's likely to be the light switch.

Thanks for the replies.
ln the sidelight position all is OK. In the headlight position everything goes off and the main/dip stalk does nothing. Although the horn and indicators still work.
l called Land Rover and a new switch is £115+VAT!! (Britpart £12 Lucas £20 Bearmach £14)
No wonder people fit aftermarket parts. What are Land Rover thinking with these prices?

Can you flash the main beam as that has a separate supply and when it melted on mine it had only done it on one position? Also it might be worth a look at the headlight relay and base as mine melted through the insulation and was causing all sorts of issues. It is pretty easy to check the switches with a voltmeter without removing them as the contacts for the most part are exposed with the surround off.

I had a look today and the switch has melted in the main lights position.
I fitted a new switch and it works fine now. I did notice that the harness plug to the light switch showed signs of overheating (brown wire....live feed).
I checked the headlamp bulbs and they are 55/60w.
Why would the contacts have melted on the switch? Poor design? Cheap aftermarket switch? (I think a new one was fitted last year when we bought it)

Cheap switch or a loose connection can cause overheating. Have you got any additional lights wired to the headlamps? If so they should run via a relay. Most peeps just splice them into the existing wiring which melts the switch.

No there's nothing else connected. The missus is blaming me as l fitted the wiring for the heated screen last week.
But l never touched the wiring for the lights. The heated screen relay connects directly to the battery via a fuse.

It's a very common fault, the full current runs through the switch. Over time the contacts degrade with use and the resistance increases, generating heat which eventually melts the surrounding plastic enough to mean the contacts no longer touch correctly. Piggy-backing extra lighting as mentioned above speeds this process up somewhat, as does the use of cheap aftermarket switches.

The proper solution is to run the headlight power supply through relays, this takes the load off the switch and prevents the issue reoccurring. It also has the added benefit of increasing the voltage the bulbs see due to lower wiring losses, which can have a dramatic positive effect on light output.

Google 'defender headlight relay loom' for pre-made solutions, or buy some wire and relays and make your own.

Great thanks for that, l'll fit the wiring modification.
l imagine the system was designed in the days of 30/40w headlamp bulbs and now they fit 55/60w.

Alas I fear it's just crap design, rather than that.

Land Rover, Lucas, or the British car industry in general does not have the best of reputations for electrical reliability.

Lucas, Prince of Darkness rings a bell! That said, I did replace my indicator stalk with a Lucas one and that has been working well for the last couple of years