Which One's the Headlight Relay

[95 Disco]

G'day,

On a 95 Disco, is the headlight relay behind the glovebox, and if so, which one is it? ... x from the left or whatever .... the vehicle's not here at the moment so I can't trace the wire colours ... assuming Brown-Orange / Brown-Purple and Blue-Red / Black

For future reference, is the physical location described in RAVE or Haynes, 'cos I can't find it ... the relay or a reference.

Please don't assume that I know what I'm talking about :(

Thanks

Grant

[dmdigital]

I thought the headlight relay was in the fuse box under the bonnet.

[95 Disco]

I thought the headlight relay was in the fuse box under the bonnet.

Thanks DM... now I'm even more confused... or even 'fused

[ladas]

According to my wiring diagrams - there isn't any relays for the headlights ????:o

[Utemad]

I didn't think there was a relay. Hence Drivesafe's headlight wiring loom with relays. Which is a must do by the way. My lights are so much brighter now.

[langy]

95 Disco's don't have factory headlight relays - upgrade is the best idea.

[95 Disco]

To explain further (and incur the wrath of "why didn't you say that in the 1st place"), I've got the same problem as -

http://www.aulro.com/afvb/showthread.php't=24770

with flashing high beam OK, no "stay on all the time" high beam, and no low beam at all. I've wiggled the wires at the back of the column switch, furthest to the left, kicked the tyres, lit the fires, etc, etc... The auto sparkie says the switch is OK. Coincidentally, or totally related, the interior light (above the rear view mirror), has also given up. Fuses and bulbs are OK.

Thanks for the comments so far

... ain't life grand ....

Grant

[Utemad]

My money is on the switch even though it tested ok.
The auto sparky probably tested it with a multimeter and it would test fine. However the contacts will be burnt from switching the current for the lights. This means that the contacts will pass a continuity test but will fail under load.

Then again it could be something completely different.

[95 Disco]

Thanks UteMad,

First task is driving when the Sun's down, second task, or requirement, is the headlight wiring loom upgrade.

But being a big boy and therefore being allowed out at night would be good ...

[ladas]

To explain further (and incur the wrath of "why didn't you say that in the 1st place"), I've got the same problem as -

http://www.aulro.com/afvb/showthread.php't=24770

with flashing high beam OK, no "stay on all the time" high beam, and no low beam at all. I've wiggled the wires at the back of the column switch, furthest to the left, kicked the tyres, lit the fires, etc, etc... The auto sparkie says the switch is OK. Coincidentally, or totally related, the interior light (above the rear view mirror), has also given up. Fuses and bulbs are OK.

Thanks for the comments so far

... ain't life grand ....

Grant

Why didn't you say that in the first place :D :D :D :D ;)

Now I have looked at the diagrams, and if the switch is really okay, then the only thing between the switch and the headlights is a second set of fuses in the facia.................

However as the Headlight flash goes through the same fuses we should be able to discount that. Plus as the lights do still work on headlight flash we can just about assume that it isn't down to dodgey earths (I normally blame those for everything)

I think.....................it has to be the switch.

Do you have a wiring diagram ?

Have you got a test meter ?

[Utemad]

If it were my car I'd use a multi meter to check for 12v in and out of the switch. Both under load and not under load (i.e take the bulbs out or unplug outgoing connector if it is seperate to ingoing connector).

Then if it is the switch I'd try and pull it apart. Then when I broke it I'd short the appropriate wires to make the appropriate lights work until the new one turned up.

[95 Disco]

Hi Ladas

Re: Do you have a wiring diagram ? Yep
Re: Have you got a test meter ? Yep
Re: Do I know what I'm talking about? Nup

Thanks all for the comments (keep 'em coming). Back to the sparkie tomorrow... and I'll "read the manual" (IAEF) on getting the steering wheel off to replace the switch ...

[ladas]

wiring diagram - and connector view attached

[ladas]

I peaked too soon with the diagram.

However we now have a common one so hopefully you will understand what I am gibbering on about...............:D

Underneath the steering col shroud there is a 7 posn connector (white one) view of connector is in the attachment

If you unplug it, and check terminal 6 (top middle of the three, not 4)

You should have 12v (+/-) that is the live supply.

Get a small piece of wire and bridge the connectors between terminal 6 and terminal 5 this should give you dip beam.

Transfer the bridge from terminal 5 to terminal 3 this should give you main beam.

If all these check out then we are back to the switch.

Plud the connector back in, and this time switch the head lights onto dipped beam you should have 12v at term 6 (brown/purple wire) and term 5 (blue/white wire) you should also have 12v

If no voltage at 5 then it's the switch (we should have already checked 6 above)

[95 Disco]

Cheers, Lada

Gibbering I like ... I can identify :D

Particularly like your gibbering about jumping connections, which I'll do tomorrow... and advise. Go to bed, it's late in (wonderful) Victoria.

Cheers,

Grant

[95 Disco]

Problem solved ... it was the switch, a burr of plastic interrupting the contacts. Ladas' diagnostic methods nailed it. ONYA Ladas.

Thanks for all replies.... now for the relay upgrade...

Cheers

Grant

[Utemad]

Thanks for all replies.... now for the relay upgrade...

Good to hear. Now you can go out at night again :)

Since you have been given this reprieve I would install the loom sooner rather than later. Plus your lights will be brighter.
I made one using the instructions provided by Drivesafe in the Projects/Tutorials section. Alternatively he will sell you one already made.

[95 Disco]

Good to hear. Now you can go out at night again :).

... not dark here yet, but vaiting, vaiting ...



Since you have been given this reprieve I would install the loom sooner rather than later. Plus your lights will be brighter.
I made one using the instructions provided by Drivesafe in the Projects/Tutorials section. Alternatively he will sell you one already made.

Ready made sounds my style .... do I PM Drivesafe, ask nicely and quote plastic card numbers ?

...or should I do the shocks and springs all round, or the major service, or ......

Grant

[Utemad]

PMing him would be the go.

This is the thread I have referred to.
http://www.aulro.com/afvb/showthread.php't=21906

I'm not sure how urgent the other things are but this one might save you the cost of a new headlight switch unit. Would be the cheapest of the to do list though.

[dmdigital]

Just going through the RAVE CD. I was under the mistaken belief that my 03MY Disco did have a relayed head light circuit. So I'm wrong :eek:

Now before I rush off to drivesafe and order another wiring kit (one in the Defender is EXCELLENT... I wonder if he does one for H7 connects??) I also thought that you did not want to increase the power output of the 03MY Disco lights as this can lead to issues with the polycarbonate covers. So given I don't need to increase the bightness of my lights with higher wattage bulbs, but, given that a wiring kit would effectively increase the power to the bulbs above designed housing's potential is this the way to go?

What has anyone else done to the lights on an 03MY Disco??

[ladas]

Just going through the RAVE CD. I was under the mistaken belief that my 03MY Disco did have a relayed head light circuit. So I'm wrong :eek:

Now before I rush off to drivesafe and order another wiring kit (one in the Defender is EXCELLENT... I wonder if he does one for H7 connects??) I also thought that you did not want to increase the power output of the 03MY Disco lights as this can lead to issues with the polycarbonate covers. So given I don't need to increase the bightness of my lights with higher wattage bulbs, but, given that a wiring kit would effectively increase the power to the bulbs above designed housing's potential is this the way to go?

What has anyone else done to the lights on an 03MY Disco??

The wiring kit will not increase the brightness of existing system - it just removes the risk of overheating/burning out the switch and/or cable.

Long as the volts are the same it wouldn't matter if you connected the lights direct to the battery - they will not increase the power / brightness.

Resistance like light bults (as long as the volts are correct) take the power (amps/watts) that they need. To increase brightness you either up the rating (watts/amps) of the bulb - or increase the voltage - until it's over volts and then it will blow.

If you take a standard 12v bulb and apply a 12v supply at 4 amps you will get the same brightness as if you put a 12v supply at 40 amps.

But if you put 15v onto the bulb @ 4amps - your bulb would be brighter (but would not last too long).

[Utemad]

When I installed my loom I originally fitted it to one headlight only to gauge the difference. Not only the light output was greater but you could feel the increase in heat. However I doubt that the increase in heat would affect the headlight housing since surely it would have been designed to cope with the full power of a 55/60w bulb. Not the decreased output due to a dodgy Land rover wiring design.

[dmdigital]

Isn't the purpose of a wiring upgrade (in this context) to improve the power delivered to the bulb. So a 12V 55W bulb does actually get the correct 12 volts to deliver 55W and doesn't suffer from voltage drop due to resistance in the wiring?
Therefore by improving the power at the bulb it will generate more heat as it is working at closer to full efficiency than it was before.


I also suspect that it would be OK to run 60W low and high beam bulbs in the Disco 2 head lamps instead of the 55W and 60W that are the default.

[Utemad]

Long as the volts are the same it wouldn't matter if you connected the lights direct to the battery - they will not increase the power / brightness.

That is true but in the case of this system the shorter and heavier wiring does increase the voltage at the bulb. Therefore as you said the bulb will glow brighter (and hotter). But no brighter than it was designed to.

[ladas]

That is true but in the case of this system the shorter and heavier wiring does increase the voltage at the bulb. Therefore as you said the bulb will glow brighter (and hotter). But no brighter than it was designed to.

Yes well pointed out - and again as you pointed out - no brighter than they were designed to operate at.

Or more to the point, most car bulbs operate at less than they are designed to, due to the voltage drop through, wiring, switches, relays etc.,

[ladas]

Isn't the purpose of a wiring upgrade (in this context) to improve the power delivered to the bulb. So a 12V 55W bulb does actually get the correct 12 volts to deliver 55W and doesn't suffer from voltage drop due to resistance in the wiring?
Therefore by improving the power at the bulb it will generate more heat as it is working at closer to full efficiency than it was before.


I also suspect that it would be OK to run 60W low and high beam bulbs in the Disco 2 head lamps instead of the 55W and 60W that are the default.

From my understanding - and I am sure somebody will correct me if I am wrong - the purpose of the wiring kit is to remove the high current (amps) draw through the switches - which are the weak link when relays are not incorporated, and to ensure the correct voltage (reduced voltage drop) arrives at the bulb.

I'll do a quick diagram to explain my reasoning and post it.

[dmdigital]

Yes well pointed out - and again as you pointed out - no brighter than they were designed to operate at.

Or more to the point, most car bulbs operate at less than they are designed to, due to the voltage drop through, wiring, switches, relays etc.,

So back to my question. Improve the wiring (decrease the voltage drop), bulbs operate at higher efficiency (closer to 55W and 60W) and therefore may generate more heat. How does this all effect the polycarbonate lighting lens on the D2a?

[ladas]

So back to my question. Improve the wiring (decrease the voltage drop), bulbs operate at higher efficiency (closer to 55W and 60W) and therefore may generate more heat. How does this all effect the polycarbonate lighting lens on the D2a?

If the lense is designed to run with 60w bulbs at optimum voltage (anywhere up to about 14v) and the 60w bulb is as specified by the manufacturer (ie LR) then I am sure that there will be no effect.

...............but I wouldn't be tempted to go over 60w

[dmdigital]

If the lense is designed to run with 60w bulbs at optimum voltage (anywhere up to about 14v) and the 60w bulb is as specified by the manufacturer (ie LR) then I am sure that there will be no effect.

...............but I wouldn't be tempted to go over 60w

No I wouldn't either. The more I think about it the less inclined I am to improve the power supply to the lights. The Disco's are bright enough anyway.

[ladas]

No I wouldn't either. The more I think about it the less inclined I am to improve the power supply to the lights. The Disco's are bright enough anyway.

Sorry to go on - but I think you are missing the main point of the upgrade.

Many vehicles, LR included, power the headlights directly through the switch - as can be seen from this web site - this is the weak spot. The switch fails with overheated, or sometimes melted contacts/plastic.

The brightness of the lamps is, in my view the secondary issue.

Now I don't know if they have resolved this on the D3, but the problem is very apparent on the rest of the LR range.

[drivesafe]

Now I don't know if they have resolved this on the D3, but the problem is very apparent on the rest of the LR range.

Hi ladas, the problem is solved once and for all, in the D3, RRS and MkIII RR. They don’t have headlight light globes any more because they are now equipped with HID headlights.

Cheers.

[Wazza]

Hey Drivesafe

don't you put out a upgrade kit?

If so whats the cost for a 300tdi?

How hard is it to fit?

Cheers

Wazza

[ladas]

Hi ladas, the problem is solved once and for all, in the D3, RRS and MkIII RR. They don’t have headlight light globes any more because they are now equipped with HID headlights.

Cheers.

Thanks mate, I'll pop that info into the old memory banks for future reference.

[dmdigital]

Sorry to go on - but I think you are missing the main point of the upgrade.

Many vehicles, LR included, power the headlights directly through the switch - as can be seen from this web site - this is the weak spot. The switch fails with overheated, or sometimes melted contacts/plastic.

The brightness of the lamps is, in my view the secondary issue.

Now I don't know if they have resolved this on the D3, but the problem is very apparent on the rest of the LR range.

Under normal load the switch should not burn out. It is designed to take a limited current and should be OK. The trouble comes when you try to draw more current than designed and of course this is what happens when you put higher wattage bulbs in or have a fault. This is something I'm not intending to do in the Disco due to the polycarb lenses (fault though may be unavoidable).

All that said though, the only protection for the headlight circuit is therefore the high/low fuses and this doesn't prevent the switch from suffering if there is any issue with the headlamp circuit. By moving the lamp circuit to a separate relay triggered circuit you remove all the problems.

As for the D3. I think its almost correct to say everything electrical goes through 1 of the 25 or more ECU's and as drivesafe pointed out they now also have HID's.

As an aside it is possible to destroy the ballasts of some HID's due to excessive vibrations in the vehicle (e.g. in D11 Dozers). Not something I think is a D3 issue!

[95 Disco]

This is starting to sound like a "how many x's to change light bulb" story .... 16 posts to solve the problem, 16 posts to discuss the solution.

But: if the current, the flow, the amps, the stripping of atoms from cathode to anode (or is that anode to cathode), is reduced by the introduction of the relay upgrade to drop the current through the switch ... ain't that "a good thing" for the switch :unsure:

But, more to the point, it's dark here ... and I've been allowed out without the intervention of Mr. Plod. Ladas (& UteMad) said let there be light, and I can see for bloody miles ... even more, perchance, when I install the relay kit...or not.. same 'light' just reduced atomic erosion of the switch.

[dmdigital]

This is starting to sound like a "how many x's to change light bulb" story .... 16 posts to solve the problem, 16 posts to discuss the solution.

:twobeers: :beer: :clap2:

[drivesafe]

OK some suggestions and solutions.

Hi Wazza, yes, I do have a range of Headlight Wiring Upgrade Kits and their prime objective is to brighten the light being putout by the headlight globes and to do this the existing headlight wiring is replaced by heavier wire, set up in a shorter run, this double improvement increases headlight output considerably but a side benefit is that the load through the headlight switch is reduced to about 1/50 of the current it normally handles and this improves the life span of the switch.

The improved voltage will increase the heat but not to a point where it becomes a problem for the headlight plastics. I have not heard of anyone having a problem in this area.

If you are still concerned about the potential heat problem then change the globes to Philips Crystal Vision globes. Same power as a 55w but much better light.

I use to run 130w globes in Hella 181 driving lights and they would have burnt reflectors in about two years if I was luck.

I’ve been running the Philips globes in the same Hella 181s for just over 4 years now and they are as good as the day I bought them and you can’t beat the light.

Cheers.