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faulty lights

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hi folks,

got a typical Lucarrrrse electrics problem on my 90. Front lights appear to have stopped working :angry:

flick the switch to side lights - little side lights work, side lights in the headlight bowls work. Cool

flick the switch to dip beam - little side lights work, nothing is on in the headlight bowls. NOT cool

main beam - all works ok.

so for some reason all power seems to evaporate when dipped is selected - fuses are all ok and the bulbs are fine.

Any pointers on what i should be checking to find out why dipped has suddenly decided to abandon me?

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where is the dim/dip relay and how do you test it?

sorry to sound dense, but i dont do hellecktricks and i dont particularly understand it either. mechanical spinny bangy things - yep! - invisible forces that make your body twitch and burn yer fingers.....nope!

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i tried tickling it - didnt work. :(

however i did get the multimeter out and have the following results - means absolutely NOTHING to me, but one of you kind peeps might know what it means


engine on for all tests

switch at first position:

sidelights come on, very dim bulbs in headlights

on top of the column switch - brown wire 12v, red wire 12v, blue wire 0v

switch at second position:

sidelights on, no lights at all in headlights

on top of the column switch - brown wire 12v, red wire 12v, blue wire 12v

I think this means the column switch is ok.

Full beam flashes ok no matter what the lights are doing and full beam comes on ok when headlight switch at second position. I think i can presume the wires to the headlight bulbs are ok, or they wouldnt work at all. Same for the earths. Bulbs must be ok too.

All fuses ok

rear lights are fine no matter what as well.

took dash off:

found a pink relay, part number YWC 10050

when you turn sidelights on, you can feel a click inside. When you turn main beam on, you can feel a second click inside.

Took pink relay out, sidelights come on ok - but no dim in the headlights. Turn main beam on - nothing.

ermmmmmmm sure this means something to someone, but not to me. I'll hazard a guess that the whatsit that does the doobry thingy aint working.

Any help would be hugely appreciated!

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main light switch on first click should give the 2 small sidelights [above indicators] & dim dip headlights [if fitted/working]

2nd click should give sidelights & normal dip beam [dim dip is auto disabled]

pink relay is the dim dip unit on your vehicle.

there should be a headlight relay behind the fusebox metal plate -- could be this is dead/intermittently faulty.

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according to this thread - http://forums.lr4x4.com/index.php?showtopic=61513&st=0&p=534240&hl=+main%20+beam&fromsearch=1entry534240

the light relay is one of the two yellow relays, swapped them over and still the same.

or is this a different relay as he is talking about a 200tdi and mines a 300? Any idea which colour it is, as there are 2 behind the fuse panel, a red and a black one.

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The first relay (C282 connector) is a yellow relay below the fuse box. This is unlikely to be the cause of the problem as it's ignition switched and also supplies power to the high beam "flash" circuit. If it wasn't working then the high beam flash wouldn't work either.

The Dim Dip relay is the most likely source of the problem and is the best place to start with a multimeter as all the required circuits go through it. As has been said already it's a pink coloured "relay" that sits behind the fascia on the right hand side. It has 8 wires going into it, The first two you need to check are the two Blue/Red wires. In normal use with the ignition on and the lights on dipped beam you should get 12v at pin 8 (the supply side) and pin 2 (the output of the dim/dip relay). If you have 12v at both then the dim/dip relay is OK. If you unplug the dim/dip you can test the rest of the circuit (or as a "get you home" fix) by removing the relay and putting a jumper wire between these two pins as that will effectively disable the dim/dip function and bypass the relay.

All the dim/dip unit is doing is providing a low voltage to the dipped beam when the lights are switched on and the ignition is turned off. One thing that is odd about your description of the problem is regarding the headlights having sidelights in them.. they shouldn't have. Are you sure it's not just the dimmed dip beam as that would change the fault substantially ? If the dim/dip is activated you'll get a low voltage reading on pin 2 (possibly as low as 2-3v).

If that is the case then check the voltages at pin 1 (white wire) and pin 5 (blue wire), they should both be at 12v - again with dipped lights on and ignition turned on.

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One thing that is odd about your description of the problem is regarding the headlights having sidelights in them

sorry - no, one light bulb - its the dim dipped thingy that turns it on.

will have a play with the multimeter again when i get home and see what the score is with regards the dim/dip relay. Damn electrics.

at least i have confirmed it isnt the column switch, stole one from my mates defender who works round the corner. Unfortunately his doesnt have a pink relay or i would have swapped that to test as well.

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OK, in that case it's almost certainly the dim/dip relay that is faulty as the only way that can happen is if it is activated. Having 12v on the blue wire and the white wire should cause the relay to deactivate giving you "full" dip beam voltage. Removing the relay and putting a jumper wire between the two blue/red wire connectors will fix it until you can source a replacement relay. I might have a spare here somewhere, I'll have a dig through my spare looms on Saturday.

If you don't have 12v on either the blue or the white wire then you have a bad connection somewhere in the loom but it's very unlikely to be the case as you'd see all sorts of other things not working.

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cheers dave - will have a go at that this evening.

if jumping the relay does work, it can stay that way! no point having it there if its not entirely necessary. I am inclined (read - hoping) it is that, as all the other light functions like full beam work, so i cant see how its the main loom to the lights themselves.

Eventually i will have enough spare parts not refitted to weigh in at the local scrappy :ph34r:

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damn and blast - i could set fire to this thing if i had some petrol and it wasnt snowing snow much!!!!

Tested both blue/red wires. on sidelights i had low voltage - which is what it should do and dim dipped headlights.

on second click of the switch i had no voltage to one of the blue red wires. BINGO! faulty relay.

chop both wires and put in a nice fat wire between them.

test again.



ok, ok, calm down. lets be logical. Test the wire coming from the dimpdip resistor, yep 12v. cool. test the blue and white wires, all in order. Brilliant, so far so good.

Look at wiring diagram and notice the blue red wire splits at some point from behind the dash to feed both the fuses. Pop the fuses out and yes i am getting 12v at both fuses. Cool, so the wiring fault isnt between the relay (that i have just bypassed) and the fuse panel or any of the other feed wires and stuff from the column switched etc.

but that just leaves the wires from the fuses box going to the headlights themselves! i think...not sure, as when the dimdip relay was in i was getting a glow from the headlights before, so i presumed that part of the wiring was ok!

so pop the lights out and see there is a blue, a black and a blue/pink going to each plug. on dipped i get nothing anywhere. On main beam i get full voltage to the blue wire. Therefore the blue pink wire must be for the dipped. Strange how the wires leaving the fuse box are just solid blue, so they must change at some point somewhere.

So the ONLY thing i can think of is that somewhere between leaving the fuse box and connecting to the bulb plug there is something wrong.

any idea where the blue wire changes to blue pink and the route it takes to get there so i can start replacing the wiring, or am i missing something obvious?

cheers for any help,


ps. couldnt actually find the dimdip resistor, but as i knew which wire it was into the pink relay i could test it was getting the 12v.

pps. there is no room in there and my hands are shredded on bits of dash :angry:

ppps. i can no longer put the pink relay back in to test the blue/pink wire for the low glowy only headlamp readings as i cut the wires too close to the pink relay and cant splice the relay back in...

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small update

essentially the lighting has 2 circuits, power from battery through the switches up to the pink relay via a blue/red wire and then from the relay to the fuses and off to the lights, again via the blue red wire.

so i have bypaased the pink relay and joined both blue red wires together.


Ok, lets test the integrity of the lighting wires.

connect the battery directly to the blue red wire that feeds the fuse box. I HAVE LIGHTS!

now this is confusing, as the blue red wire from the light switch is giving 12v also, but for whatever reason when i put a load on it i'm getting nothing. So the fault MUST be somewhere between the battery and the light switch and out to the blue red wire behind the dash.

i've tested a new light switch, no joy.

i;ve swapped both yellow relays over, no joy.

now i'm stumped......

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FOUND IT!!!!!!!!!!

woo and hoo. :lol:

decided the fault must lie somewhere between the battery and the blue/red wire that goes to the fuse box. So made up a long wire and connected that to the blue/red wire that feeds the fuse box/headlights and worked my way through every joint and connection starting at the battery.

battery to blue/red - lights work

relay to blue/red - lights work

light switch input to blue/red - lights work

light switch output to blue/red - lights work

column switch input to blue/red - lights work

column switch output blue/red - lights dont work.


so its the column switch. For whatever reason with no load on it, it was showing 12v at the blue red out of the column switch - but when you put a load on it - zilch.

must be a knacked joint or something, i even tested the column switch with a small test lamp and that killed the circuit to, only thing that doesnt seem to kill the circuit was my multimeter. So its led me on a right merry dance as all along i;ve been thinking the circuit was fine past that point as it was giving 12v!!!

damn landrovers

damn electrics

damn damn damn COLD weather meaning ilve frozen my nuts off for 2 days chasing wires about and stringing 2m lengths of wire all over the place to bypass pretty much everything in the lighting circuit!

and then to top it all off, local landy place is shut so i cant get a replacement till monday.

but thanks for all the help,


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indicator stalk, cant see any loose wires on it - but as i said, output on the blue/red is showing 12v until you connect anything to it and then it dies. copes with the draw a multimeter takes, but put anything else on it like a little test lamp and it goes to zero.

just gonna buy a new one.

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yeah, i noticed all the little rocker contacts on the back of it.

Might have a quick whizz over them with some emery paper and see if things miraculously fix themselves. If it doesnt, would rather just get a new one than muck about any more.

one thing i AM going to do in the next couple of weeks is to put a big relay and new power feed to the lights in the engine bay - that way the feed through all the switches etc isnt taking any real load anymore and might make it last longer.

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Glad you've found yours - I'm in dim dip land too.....

Though I've no lights at all except for the flash, which is on a different circuit.

I hope its ok to post it here too - it might improve the scope and usefulness of the thread for people with similar problems. If its a bad idea, perhaps a moderator could split this off ?

My lights intermittently stopped working - and the multimeter showing nothing at the brown wire - so I have a small problem somewhere between the fuse (which is OK) and the light switch. I took a seperate live and fed it into the switch - and bingo lights. Then mysteriously the intermittent fault moved into its working phase ....now onto the dim dip.....

In fiddling with the switch in trying to trace the intermittent fault it fell to bits (it was a cheap replacement part). So I simply cut it off and soldered the 3 wires together from the block connector as a temporary fix until my new part arrived. However on clipping the connector in on one occasion - I lost the whole light circuit.

I'm still getting 12 V at the switch so the problem is now further 'down stream' than that - and as it affects both the side and main lights the only common denominator seems to be the dim dip relay. And true to that theory when I make the circuit I can't hear the click from it anymore.

So I've another relay on its way for me to test as I type.

I did look at joining the wires to bypass the relay - having read that its the two blue/red wires - however It just seems to have 3 blue wires coming to it and I can't see numbers on the pins... I popped the Relay open but there is no sign of it having burnt out.

So hopefully the new relay will solve things - if not any suggestions welcome as I'll be borrowing a car to travel to work until I can fix it ...

post-10144-069436300 1294512725_thumb.jpg

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the 3 blue wires going into the dimp dip relay are hard to identify, the red striping is very very thin (plus on mine they were all covered in mud, Tong lake has alot to answer for)

if you take the relay out you will see the connector block has a pink cover on it. this can be popped off. That leaves just the black plastic connector block and you can pop out each spade clip by wiggling a thin flat head screw driver down the hole whilst pulling the cable. Should make it easier to see the wire colours and put a bridge across it.

On mine, the blue red wires were the outer wires with the solid blue one being in the middle.

you should be able to tell which is the feed in, as that will be 12v and the feed out will be zero when the relay is removed (or if the relay is faulty and still fitted). Dont snip the wires off like i did - it was only after doing that i realised how easy it is the pop the connectors out of the relay block. Makes putting things back to standard much easier if you leave the wiring in one piece and just make a bridge piece out of a 6" length of 27amp wire and 2 female spade connectors.

Good luck!

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