You may find that your headlights don’t work on your Defender (mine’s a 2005, 110 Double Cab).
There are: 2 fuses, two switches, two headlights with lamp holders, and two bulbs (lamps), 1 relay and lots of wiring involved.
Each headlight LH & RH has it’s own bulb, lamp holder and fuse – for any two of those to fail simultaneously seems to me to be highly unlikely.
You’ll find lots of advice on the WWW about probable cause, and lots of misinformation ascerting one thing or another, however, I recommend you check things in this order:
Fuses – Nos 22 and 23 are both 10 Watt and located in the large fuse box in the middle front of the passenger compartment behind the gear stick (shift) below the dash – bottom row, to the right (as you look at it). The fuses may well be held in place by plastic tape like film – don‘t damage it – it’s there for a reason – to keep your fuses seated and protected.
You might find a fuse puller inside the fuse box cover which is easily removed with two hand turned knobs/screws – see above.
The location of various fuses is evident from the diagram inside the fuse box cover.
I have little or no doubt that you’ll find the fuses are fine, but it’s an easy place to start.
Bulbs / lamps removing the screws and bezels from around the headlights is really easy – from the front of the car. Remove the retaining screws and pop out the headlights [be careful not to turn the adjuster screws by mistake- carefully remove and check / test / inspect the bulbs, lamp holders and wiring for signs of blowing out, chaffing, shorts, etc. If you have a 12 V battery you can test the bulbs (lamps) [you can test them with a 9V battery but they will of course only glow dimly unless they are shot].
The Pink Relay!! To the right behind the gauges/ clocks / dash binnacle there are up to 3 relays – the extreme right is Pink; a Lucas Relay part number YWC10050L (the ‘L’ denotes Land Rover, however, any relay with the Lucas part number YWC10050 will do the job).
This relay is also used in Classic Mini and many other BL / Austin / Rover / MG cars. To remove the dash binnacle is really easy – 4 screws – one to each side towards the top – two below, again at each end – remove them and the clocks come out (if you have any lamps ‘out’ in the clocks this is a good time to swap them for new).
Pull the Relay out – there are lugs on each side that you’ll need to ‘ease’.
The Relay has 7 legs – you can’t install it the wrong way – it’s impossible. The legs are numbered 1, 2, 4, 5, 6, 7 ans 8 [no 3 and no 9].
To test to see if the Relay is at fault remove it and jumper the sockets for legs 2 and 8 – if your lights work, the fault is the Relay – if nothing changes, chances are it’s not the Relay.
If it is the Relay, you might be able to repair it, if not you can replace it, re-engineer it to be a simple jumper / bypass or do away with it and replace it with a jumper wire or Lucas alternative.
The Relay supports the Dim/Dip feature, however, it is no longer a legal requirement – if you want you can replace it with new one with the ‘L’ denoting Land Rover which will cost up to £30 – without the ‘L’ £15 – £25 – mine cost me £18.50 for a genuine, brand new one in the box from a UK ebay shop.
If you decide to do away with it, you can buy a replacement which has just two legs jumpered together you can jumper it out yourself by connecting the sockets for legs 2 and 8 with wire, or by modifying the original relay to connect legs 2 an 8 and throwing everything else away..
To do it yourself, you’ll need a couple of inches of reasonable substantial multi-strand insulated copper wire and a spade connector for each end (2).
The Land Rover method for disabling the Dim-Dip system, uses a jumper that joins the two pins in the relay socket behind the gauges. The part number is YWZ10003(L) about £15 from Land Rover.
The alternative method is to just jump the two wires yourself with some suitable connectors.
If the Relay proves not to be the source of the problem, there are three remaining possibilities:
Chaffed / damaged cables – could be anywhere and if likely to be and / or found to be the problem, be concerned – this type of fault leads to car fires!
Light switch wear / damage – the switch to the left of the steering column has three positions – off / on (side lights / Dim Dip / Dipped Beam). High / Low Beam is controlled by the multi-function stalk on the same side but higher up the column which also functions as the Direction Indicator and High Beam FLASH switch.
Either of the switches can / could be the source of the problem, however, to remove them for proper inspection requires the steering wheel to be removed, the cowlings to be removed and three looms to be disconnected.. having dismantled the steering wheel and stripped the switches out you will be able to inspect and test the switches with a meter. You will also be able to check the security of several push fit wires. You are looking for evidence of high temperature damage to contacts and plastic mouldings or lose and / or damaged connections.
Most of the LR forums and advice on the WWW puts the problem of two dead dipped beams down to the steering column switches – these are not easy to replace and / or cheap – mine were and still are fine!
My problem is (was) the Pink Relay.
Whilst switch failure may be a lot of people’s’ experience, truth is that the unnecessary Relay does just as much work as the switches, is easy to access and test, and does not necessitate stripping the steering column on a wild goose chase and forking out considerable money on a hunch. Fuse / Relay failure are pretty easy to check / confirm – dodgy switches not so much.
If your headlights fail in similar circumstances, I’d suspect and suggest your first stop should be the Pink Relay. If you want to check the fuses and bulbs first, fine, but I would seriously caution you from stripping the steering column as a first response.
A reasonable variation might be to strip the top and bottom covers off the steering column, which will enable easier access to the Relay and the Switches (in place) on the steering column, an allow you to inspect the switches and remove and test the Relay.
You will find lots of advice about the column switches on the WWW – suffice to say my problem was not down to the column switches, it was the Pink Relay and no one else seemed to be recognising this.
Let me know if I can help further?