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Discussion Starter · #21 ·
Any more thoughts Dave? I've not had an opportunity to swap the left light onto the right side wires yet, but what about the LCM? Any more ideas?

Thank you,

Paul
 

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Discussion Starter · #22 ·
Anyone? Do I de-pin and swap around the wires on the the LCM or not please? :?:

D2
 

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I would try swapping the pins at this point, but care is needed, and they are barrel type pins, so you will need the correct tool to remove them from the connector without damage.

I have a screenshot of what connector and pins on my other computer that I will post later this evening.
 

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I don't see anyway that this would cause any sort of damage, however, use this at your own risk, I have not tested this method before.

The pins that you will want to swap are the Yellow with Blue wire in pin 13 of connector 937(black) and the White with Green wire in pin 6 of connector 2039(white). The pins of the two connectors are numbered the same, as attached. You will need a pin extraction tool to do this without damaging the pins and the connector, something similar to what is in the link can probably be found at a local parts store, and should work for you. Off the top of my head, I do not recall if there is a lock on these connectors, but I don't believe there is, but look carefully before trying to force anything.

What this will do is have the power feeds from the LCM swapped from RH to LH headlamps. This will determine if the failure is internal to the LCM or in the harness somewhere. The LCM uses MOSFETs as circuit protection instead of fuses. These will effectively 'turn off' power if too much current is being drawn, and restore once the situation is rectified, similar in operation to a self resetting circuit breaker. With the RH headlamp working perfectly when plugged into the LH connector, the issue is going to be from the LCM to the RH connector(I do agree that swapping the LH lamp to the RH connector, and ensuring that it fails there would further verify this) The 'shut off' of the power supplied on the RH headlamp circuit could be the LCM properly doing its job, and there is too much current being drawn on that circuit, possible short, or even corrosion being effected by heat. Or there could be an issue internal to the LCM and it is 'sensing' too much current.

If the failure remains on the RH side(this should be tested with the headlamps in both positions just to be sure) the failure will be in the wiring, if it switches to the LH after swapping the pins, it will be in the LCM. If the later is the case, please post before buying a new one, as I would like to be absolutely certain on what I am suggesting to do here.


http://store.snapon.com/Terminal-Tools-Set-Terminal-Tool-P651269.aspx

L322 C0937.jpg
 

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Discussion Starter · #25 ·
Thanks Dave, I'll try that. I'm loathe to take the lights out again but I guess I'll have to to determine if the left hand light fails when plugged into the right hand side.

Sorry to chase you a bit but New York's finest are getting a bit bored with 'It was working when I left home officer' on the side of the road..... bless 'em.... ;)

D2
 

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2010-2012 Range Rover MkIII / L322
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I have the same issue just the drivers side has the problem. Please pm me if you find the solution.
 

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Discussion Starter · #27 ·
I have the same issue just the drivers side has the problem. Please pm me if you find the solution.
Of course, but if I fix it I'll share it on here. First thing to do is to remove and swap your head lamps left to right. Leave the entire but plug them in the wrong sides. Of course you can't drive like that, but you'll see what happens to the fault. This has the effect of ether proving it's a harness/signal issue, or a component issue if the fault swaps sides. If it does, start swapping parts in the lamps, like ballast, bulbs and ignitor to narrow down the culprit.

Once you've done all that, and you decide it's a harness/LCM issue (under the passenger A pillar) then we can talk again.

Don't throw parts at it yet, you have to eliminate possible causes first. That way, you'll avoid all my mistakes and expense!

D2
 

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Discussion Starter · #28 ·
Typos fixed.. (too late to edit):

Of course, but if I fix it I'll share it on here, on the thread. First thing to do is to remove and swap your head lamps left to right. Leave them entire but plug them in the 'wrong' sides. Of course you can't drive like that, just leave them resting on the slam panel/air cleaner etc, but you'll see what happens to the fault, with them both plugged in the opposite sides and illuminated. It's a bit of a stretch, so be careful with the plugs and harnesses.. This has the effect of ether proving it's a harness/signal issue, or a component (within the headlamp assembly) issue, if the fault swaps sides. If it does, start swapping parts between the lamps, like ballast, bulbs and ignitor, to narrow down the culprit.

Once you've done all that, and you establish it's not a parts or wiring issue, it's probably the LCM (under the passenger A pillar) then we'll talk again. I'll post up any things I do to mine (such as swapping feeds) on here.

Don't throw parts at it yet, you have to eliminate those possible causes first. That way, you'll avoid all my mistakes and expense!

I've not plugged my left hand lamp into the right hand side yet, so I can't confirm it's possible, maybe have to remove the air box, or have the lamp hanging out the front....? But the right lamp can definitely be made to plug into the left side, resting on the slam panel.

D2[/QUOTE]


[QUOTE=Discovery2;748322]Of course, but if I fix it I'll share it on here. First thing to do is to remove and swap your head lamps left to right. Leave the entire but plug them in the wrong sides. Of course you can't drive like that, but you'll see what happens to the fault. This has the effect of ether proving it's a harness/signal issue, or a component issue if the fault swaps sides. If it does, start swapping parts in the lamps, like ballast, bulbs and ignitor to narrow down the culprit.

Once you've done all that, and you decide it's a harness/LCM issue (under the passenger A pillar) then we can talk again.

Don't throw parts at it yet, you have to eliminate possible causes first. That way, you'll avoid all my mistakes and expense!

D2[/QUOTE]
 

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Discussion Starter · #29 ·
Swapped the LCM and the problem stayed exactly the same. This has to be a loom/resistance issue somewhere.. Will de-pin the connectors and revert. The tool I ordered didn't fit the terminals I needed to remove.... :sad:
 

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Discussion Starter · #31 ·
I have a complete, functional spare passenger headlight if you'd like to borrow it :)
Thanks mate, generous offer, but I'm not sure the light unit is at fault. When I removed and plugged the left hand light into the right hand light plugs, and vice versa, the fault stayed on the right hand side of the car, with the left hand light plugged into it. i.e. the left hand light failed when plugged into the right hand side. The right hand light stayed illuminated with no issues when plugged into the left hand side of the car for far longer than it took the right hand side of the car to fail.

My conclusions?

1) It's a Range Rover, so get over it.
2) It's English so why am I applying any logic to it?
3) An unfortunate electrical fire should be convincing....`)


D2
 

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So you swapped the LCM and that still had no effect? Seems there isn't much left now. Its pretty much down to the wiring between there and the light. Typical LCM symptoms are lots of different lights flickering so seemed unlikely anyway...
 

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My right hand light just went out this week. When I turn the car on the light powers up - flickers after about a minute - then turns off. Although the xenon bulb goes out the halogen bulb will stay illuminated.

D2 - Did you ever resolve this problem? If so - what was the fix?
 

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Discussion Starter · #34 ·
Buddy, no, sorry, I've been very lazy and lived with it, BUT, what you have done is motivated me to do go outside and check the wiring between the LCM and the light itself. That appears to be the consensus of where the issue is. I guess it makes sense, and also it's interesting that it is your right hand light that is failing. I can imagine a slowly corroding wire causing resistance issues....

You can swap every individual component from left to right, bulb, ignitor, ballast, and even headlight unit itself. The light unit will plug in but obviously not install. This is a god way or ruling out components within the system.

As I understand it, the LCM is responding correctly to 'trouble' within the circuit by shutting down the light. It will restart again, up to the point where the MOSFETS (sort of fuse thingy) in the LCM interrupts the current supplied.

Not sure how handy you are, but let me know if you need more help or the wiring diagram.

D2
 

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Discussion Starter · #35 ·
I'm getting no where with this. I tried to put an LED in the power wire out to the headlight unit. When the LED is in circuit on either the yellow with blue or white with green wires, on turning on the headlights, the LED flashes five times, then goes out, then flashes every 30 seconds or so. I'd like to think that's some diagnostic signal, but I doubt it... Should those wires have 12V out to the lights? Mine show no power.

Thanks, D2
 

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Discussion Starter · #37 ·
Sounds like a plan, but only if my power supply is good. Let's get this done!

Glad you're all good.

D2
 

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Discussion Starter · #38 ·
OK, so having swapped the feeds out of the LCM and the problem remaining on the right hand side, tonight I thought 'F-it' and cut the yellow with blue feed wire to the right hand light, about 6" from the light. I then capped that end of the harness, and ran a new wire through the engine bay around the door jamb and down to the LCM which I have laying in the passenger foot well for testing purposes (times!). I then connected that end of the new wire to the yellow with blue right hand feed wire out of the LCM and capped the other end of the now redundant harness wire. Having done that, I took a healthy step back, turned the car on, turned the lights on and TADA! All is working properly. Mayybeeee the right light is dimmer than the left, maybe not, but it's just different, you know?

No smells, no heat in the wires, no issues.

All was good for a whole 20 minutes (much longer than before) and then 'flash' and light out.

Bugger.

D2
 

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Wanna borrow my lighter???
 

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Discussion Starter · #40 ·
Yep, I feel an unfortunate electrical fire coming on.....

D2
 
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