Defender 2008 interior lights not working

Gents Hi,

Im sure I have seen a thread on this but I cannot find it on the search.

Anyways my alarm/central locking seems to work it locks anyway.

The interior lights on the middle setting do not come on when the car is unlocked or when I open a door like they should.

They do work if I manually slide the switch.Its only a matter of time till I leave them on!

I have read that its somehow linked to the alarm but can anybody point me in the right direction.

As a by the clock doesn't work/illuminate, probably totally unrelated.

Hope you can help.

Regards

Chris

I'm in the same position, so would be interested in seeing the response?

I'm assuming its like any other door and the interior light is controlled by a courtesy light switch like this Defender Courtesy Light Switch AFU4241L

My next job is to see if there is 12v at the courtesy switch, hoping there is and that means the switch is knackered.

Courtesy switch on pillars is an earth, could be corroded, pop screw and switch out and look for the greenness
10as module does regulate the interior lights control and has inputs from sed switch, if you arm the alarm and manually open the drivers door with key does the alarm trigger?

The clocks are common for blown bulbs and the main dealer will supply a new bulb but sadly only as part of a new clock assembly hmm anyone on here that can supply a part number or type for said bulb?

I located the switch on the pillar and tested the continuity and the switch was operating fine. However I did remove the positive and place on the metal hole to earth and the lights still didn't work!?

When i arm the alarm and open doors manually the alarm does sound. Funny too, when I arm the alarm the interior courtesy light does flash on briefly.

Any ideas?

Open door equals alarm means the pillar switches are workin
It's a 10as fault I'd say
Pop out the drivers side lower speaker and undo the 2 plugs
There's 2 small torx screws holding the 10as on I'd be interested to know if wiring is ok from 10as to interior lamp and whether any rain water has got onto 10as
The latest defender uses a revised black alarm unit but not called a 10as anymore
It is multi compatible with newer and older models

It needs prog to either old type 433 hz or new type fob 434 hz
Set up is done with land rover sdd but retro fitting into an older truck to utilise new type fobs requires some additional wiring and an rf fitted
I'll do a thread on it when I get the chance

Here's what your 10 as plug wires do





Hope this helps

Grey connector pin 1 supplies power to interior lamps
Pin 16 is a spliced join which is fed by all door pillar switches except drivers door
Pin 5 is drivers door pillar switch
Check these first

Sorry for delay in coming back
Mine is exactly the same arm the alarm and manually open the door the horn sounds.
Also on locking and unlocking the interior light flashes for a second.
I will take a look at the module behind the speakers later and try and get some pics.

Pull off the cover of the interior light and remove the bulb. You are getting the permanent live as the light works in the manual position so connect a bulb tester or multimeter between each side of the bulb and switch on. You should see it light up/register 12v..... Now touch one side of the tester to one bulb contact and the other to ground (handbrake bracket is a handy ground). Does it also register 12v? If not touch to the other side of the bulb holder. Does it register 12v? When you have found the side that registers 12v you have the LIVE side. The other side is the ground side. Pull the door switch out and test the continuity between the electrical connection on the rear of the switch and the ground side. If it is ok then the issue is the door switch or most likely corrosion. Clean up the switch and refit. Do the same for both sides and re-test.

If that doesn't work it could well be the switch of the interior light itself which is corroded. You can test that by removing the interior light and pulling the electrical connector off. Once off connect a multimeter between the permanent live and door switch ground wires then opening the door. If the meter/bulb tester registers 12v then your interior light fitting is faulty. They can usually by cleaned up though.

My electrical tutorial - http://www.landyzone.co.uk/lz/f38/tutorial-car-electrics-245168.html

Had a look underneath and cannot really see any signs of water damage.

When you say check pins 1 5 16 first what did you have in mind?

Cowasaki I have dusted off the multi metre I seem to be getting 12v on both sides of the terminals until I switch the slider to off or on?

Going to check the door switches now.

OK so by definition and a length of wire I have determined I have an earth at the door switch BUT it doesn't appear to be getting to the light fitting and making it work.

My method a length of wire making contact with the bodywork and then the earth side of the light found that side after I blew a fuse. it lights up fine just not with the door switch located and fixed.

So I took a look at the fitting certainly no corrosion looks ok so I checked the connections just to be sure BUT I did find a stray purple wire see attached doesn't seem to have a home?

Any thoughts, not sure this is my problem but worth asking.

If it looks like a 10as fault, I have come across this guy does anyone have any experience of him? He says he can fix the fault?

Land Rover 10AS Alarm Programming + 2 Keyfobs + EKA Code for Defender/Disco 1 | eBay

Interesting as I'm meeting a local chap tonight who has a Nanocom unit and he is reprogramming a new key fob I have, I'll ask him about the interior light.

Keen to see his thoughts and how you get on.

Good and bad news for me. He reprogrammed the new alarm fob I bought no problem for £30.

However he could not find any problem with the 10AS. Using his box of tricks (a T4 box not Nanocom) he couldn't diagnose the light problem.

Not sure now!?

I think I am going to tap up the chap in Brighton and see if he can get to the bottom of it. My fear is that some numpty has bodged up the wiring in mine?
Fingers crossed its the 10as unit though

Sorry to dig up an old thread, but its the most relatable one I've found. Picked up my first Defender (2005 TD5 110) last weekend, and I've got to sorting out a few niggles I've noticed since collecting it.
My rear door and drivers door where not turning on the courtesy lights inside, rear door was an easy fix. The spade on the switch had corroded, new one on and that was it sorted.

However, my driver door isn't so simple. On inspection the switch/spade/wire seem in good shape. I've connected a multimeter to the switch wire and to the ground in the pillar and I don't get any readings. I'm stumped as to what I can do further to diagnose to see if its the wire or a ground problem.

Can anyone provide any information as to what I can do next to see where the problem is?

Thanks

hunter_pa said:

Sorry to dig up an old thread, but its the most relatable one I've found. Picked up my first Defender (2005 TD5 110) last weekend, and I've got to sorting out a few niggles I've noticed since collecting it.
My rear door and drivers door where not turning on the courtesy lights inside, rear door was an easy fix. The spade on the switch had corroded, new one on and that was it sorted.

However, my driver door isn't so simple. On inspection the switch/spade/wire seem in good shape. I've connected a multimeter to the switch wire and to the ground in the pillar and I don't get any readings. I'm stumped as to what I can do further to diagnose to see if its the wire or a ground problem.

Can anyone provide any information as to what I can do next to see where the problem is?

Thanks

Click to expand...

Several things....

Test the door switch wire:

Connect your multimeter so that one of the cables is touching a good earth such as the handbrake bracket and switch the multimeter to diode test/or resistance. now to test the multimeter touch the other cable against a good know other ground such as the door catch bolt. If it sounds you have a ground test device in a working condition. Now touch this against the wire from the back of the door switch and nothing should happen..... Now open the passenger door and touch the multimeter against the wire..... It should sound/indicate nearly zero resistance.

If this doesn't work like that you may have a broken wire to the door switch which is somewhat unlikely.

Test the ground of the body at that location:

With the multimeter still setup as above touch the body at the location where the screw goes through and it should indicate ground. If it doesn't then clean up the area and test again. If you still have no ground pull a wire from a good ground to that location and attach it using a ring crimp and a second hole BUT this really shouldn't need doing it is likely just corrosion.

Test the switch:

Have a look at the door switch. Is the moving section making good contact when in the open position? Test the resistance across the switch from the screw hole to the contact with the switch open and closed.


Put it all back together.

Use a new screw and put copper slip in the hole. Make sure the switch is located correctly and screw it in. With the above checks done it should work. If it doesn't then either the screw isn't making proper contact with the switch or body or alternatively there is another issue with the switch. You could test that by swapping left and right ones. If the fault moves then replace the switch.