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TeZZaP
18th August 2008, 08:26 AM
Hi guys, I have a problem with the lighting circuit on my 2003 Defender 90.

I have no main beam, or dipped beam, but the flash still works. Additionally the front side lights come on when you switch the lights on but go off when you move the switch though to main beam. Plus the fog light has stopped working.

I have checked the fuses plus all the connectors I can find, and all appears OK with those.

I only have an old Hayes book for electrical diagrams and that only goes up to 1995, so I'm not working with the current electrical diagam, but it appears that the rear fog light, main beam and dip are all related, I was thinking either the voltage regulator is playing up or maybe (more likely) the Rear foglight inhibitor relay has gone and taken out the main beam and dip circuit with it...

Any thoughts... and does anyone know where I can get an up to date wiring diagram for my 2003 Defender 90?

Tar

TeZZa

dmdigital
18th August 2008, 08:40 AM
RAVE CD for the Defender covers up to 2003 and has the wiring diagrams.

TeZZaP
18th August 2008, 08:49 AM
RAVE CD for the Defender covers up to 2003 and has the wiring diagrams.

Thanks, I'll track it down

foz.in.oz
18th August 2008, 09:31 AM
This is a failure of the lighting switch itself. it is a common fault and has been spoken about loads of times on hear before.

Quick emergency fix. cut and twist the three wires together on the back of the switch.
or wire a 40 amp relay in position in stead of the switch and wire a switch to turn this on,
or buy a headlamp upgrade kit that bypasses the switch thus not burning it out (new switch needed),
Or buy a new switch (and a spare for when it blows again).

TeZZaP
18th August 2008, 09:39 AM
This is a failure of the lighting switch itself. it is a common fault and has been spoken about loads of times on hear before.

Quick emergency fix. cut and twist the three wires together on the back of the switch.
or wire a 40 amp relay in position in stead of the switch and wire a switch to turn this on,
or buy a headlamp upgrade kit that bypasses the switch thus not burning it out (new switch needed),
Or buy a new switch (and a spare for when it blows again).

Thanks for this info; I actually narrowed it down to the switch when I first checked though everything this morning, but then didn't have enough faith in my reasoning to carry though; I thought the switch should have show some signs of getting dirty contacts or something before actually failing.

Also, up to now I have not worked on the 90, it has a full service history(!) and I stick to rebuilding older Series Landies! However, since Land rover no longer import the SWB I guess I won't be trading her in for the latest model... I'd better get my reference tools and knowledge base up to speed!

Thaks again

TeZZa

NB I did do a search on here for electrical problems but obviously didn't put the correct terms in...

foz.in.oz
18th August 2008, 09:57 AM
When my failed it showed very little sign of there being a problem. The multimeter said otherwise. The lttle rivets that hold the contact strips to the switch body were loose though and I can only guess that oxidation had caused a break to exist. Thought I would have a go at soldering them to re-enable the conductivity but I couldn't even get the solder to wet to them.

I went for the 40amp relay route. $6 for a relay and about $6 for a switch. Wired both side lights and main lights together. All the lights come on together now rather than the side lights on their own and then mains.

TeZZaP
18th August 2008, 10:02 AM
When my failed it showed very little sign of there being a problem. The multimeter said otherwise. The lttle rivets that hold the contact strips to the switch body were loose though and I can only guess that oxidation had caused a break to exist. Thought I would have a go at soldering them to re-enable the conductivity but I couldn't even get the solder to wet to them.

I went for the 40amp relay route. $6 for a relay and about $6 for a switch. Wired both side lights and main lights together. All the lights come on together now rather than the side lights on their own and then mains.

Thanks for the info, the relay/switch sounds like a good option, did you just pop the switch into one of the blanks (I assume it was a rocker style switch to match the existing ones?)?

foz.in.oz
18th August 2008, 11:01 AM
I removed the original column mounted light switch and fitted an on/off toggle type switch in its place. Cut the wires off the old switch as close to it as possible. Connected the live to the old switch to the switched contact of the relay and to the new switch. Took the thin wire from the switch and the remaining large wire (not the live) and connected them to the other side of the switch relay contact. Connected the second wire from the new switch to the relay coil and then an earth wire from the other side of the relay coil to the chassis to ground.

see attached pic

abaddonxi
18th August 2008, 11:15 AM
Have a look here for Drivesafe's headlight wiring upgrade kit -
Dave's Interesting Things (http://www.davesitshop.com/davesitshop/index.php?_a=viewCat&catId=5)

It includes everything you need to upgrade wire thickness and install relays. Your headlight switch won't wear out, your lights will be brighter, you can install brighter globes without worries, etc. and you're helping AULRO at the same time.

Replacement headlight switches come in OE - Lucas, or other manufacturer, which is significantly cheaper. When the choice is between Lucas and anyone else, some people might think that not-Lucas is a fine idea.:D

When my headlight switch melted I put in relays and stuff, and was able to fix the switch with solder and butchery. In my case the contacts had melted into the plastic housing, so not too hard to fix, and I'm counting on the relays in the future.

Cheers
Simon

TeZZaP
18th August 2008, 02:26 PM
Thanks all - definitely the light switch, I took it out dismantled it, gave the copper rivets a bash with a punch 'cus they seemed a tad loose to me and voila, all working... well, it was for a minute, unfortunately I touched the light-switch on the ignition switch when putting it back together for the last time and blew one of the fuses below the seat! BUGGER!

EDIT to add;
Anyone know if I can just remove the big looking fuses under the seat - they appear to be screwed in place; its a 30A one?

Psimpson7
18th August 2008, 03:59 PM
Yes, you can just unscrew and replace the big fuses.

Rgds
Peter

TeZZaP
18th August 2008, 05:27 PM
Yes, you can just unscrew and replace the big fuses.

Rgds
Peter

I don't suppose I can get a replacement for this at Supercheap auto can I...