Feed off Map Light wiring working backwards!

Background:

Trying to wire up 12v external LED courtesy lights.


Wiring:

New 4 x external lights are spliced & daisy chained off existing central internal map light, 3 Landrover internal wires assumed to be:

* Permanent Live = Purple cable.
* Switched Live = Purple with white tracer
* Ground = Black

(NB: I used the switched live, not the permanent live).


Aim of function:
The aim of the external lights is to illuminate on door open/door unlock, essentially copying the factory interior map light when key fob is pressed or door opened/closed.


Problem:
Using the switched live cable, the external 12v courtesy lights illuminate but in reverse: they turn 'on' when doors are locked with key fob, and turn 'off' when doors are un-locked!!! (backwards desired effect).

If I swap the switched (purple with white tracer), for the the permanent live (purple cable), the exterior 12v courtesy lights, won't turn off at all.


Question:

Does the Freelander MK1 map light wiring utilise some kind of relay to the vehicle ECU?
What is the correct connection to make the new external lights work as planned?


Many thanks for any ideas,as I'm totally stuck and can't see any other way to power it up, using the internal map light, or more importantly, why the map light would create this error in the first place.

I'm planning on doing the same with my FL1 and was wondering how to do this. I guess that you have taken a wire from the roof light to the courtesy lights that you're fitting and then used a local earth where the lamp is. Is that correct?

I'm guessing here but may be the ECU, via a relay, applies an earth to the roof light when the doors are unlocked. So when the doors are locked the earth is removed to deactivate the roof light.

If that is so and you have wired it as I guess at the start, then you're proving a local earth over riding the ECU's, hence light on when locked / light off when unlocked.

Potential solution: Try a two wire circuit. Cut the 'switched live' wire take power from the roof lamp to the courtesy lamps and a return to the roof lamp and complete the 'switched live' circuit to the roof lamp. So power has to go through the door courtesy lights first and the roof lamp last.

If I'm right then all three 'courtesy' lights will behave like the original roof lamp.

Let me know if that works!

PS My Haynes manual circuit diagrams mention door switches but I can't for the life of me see them. Are they inside the door on the lock mechanism?

htr said:

PS My Haynes manual circuit diagrams mention door switches but I can't for the life of me see them. Are they inside the door on the lock mechanism?

Click to expand...

Inside the lock......

From memory. The interior light is fed a live feed from the CCU. This feed is via a power transistors. When the doors are opened, the CCU feeds NBV to the light, the light being earthed locally.
When the vehicle is unlocked, the CCU applies NBV to the light for approximately 15 seconds. There is a light delay too. Once the doors are shut the CCU powers the light for a short period of time. This is cancelled when the vehicle is locked, so the light goes out.
It should be ok to take the live from the Pink / White. Take the earth locally to the new lamp. Don't forget LED'S are polarity dependent.

Nodge68 said:

From memory. The interior light is fed a live feed from the CCU. This feed is via a power transistors. When the doors are opened, the CCU feeds NBV to the light, the light being earthed locally.
When the vehicle is unlocked, the CCU applies NBV to the light for approximately 15 seconds. There is a light delay too. Once the doors are shut the CCU powers the light for a short period of time. This is cancelled when the vehicle is locked, so the light goes out.
It should be ok to take the live from the Pink / White. Take the earth locally to the new lamp. Don't forget LED'S are polarity dependent.

Click to expand...

Hmm, I've tried this two ways now both without success. Taking care to get the LED polarity right I've T'd into the switched live feed, down to the LED door lamp and a local earth. The door LED stays on - no roof lamp.

I've broken the switched live feed, fed that to the door LED lamp and back to the roof light and rejoined the feed into the roof lamp. No lighting at either place.

Any advice welcome.

htr said:

Any advice welcome.

Click to expand...

Looking at a wiring diagram the Purple is defo permanent live and feeds the bulb in the normal way. It seems to me that the bulb is activated either in the traditional manner by earthing it via the switch on the roof, or via the CCU through the purple/white wire.

Working back from from the door lock the purple/white leaves as a switched earth and enters the CCU. It exits and heads up to the rooflight and becomes an option via the switch to be the earth for the bulb.

Have you tried a multimeter taking the purple as positive and the purple/white as the negative and see what readings you get whilst locked/unlocked etc?

Hope that makes sense!!

Thank you, I'll try that.

htr said:

Thank you, I'll try that.

Click to expand...

It makes sense that the CCU would apply the earth. This is in fact no different to how and engine ECU fires things like coils and injectors.

Nodge68 said:

It makes sense that the CCU would apply the earth. This is in fact no different to how and engine ECU fires things like coils and injectors.

Click to expand...

Agreed. When looking at the overall wiring diagram it was quite apparent that there's a lot of accessories constantly live (via the ignition) that are switched by the ECU via an earth supply!! Far cry from my old dynamo powered Mk 1 Escort !!!

19NMC said:

Looking at a wiring diagram the Purple is defo permanent live and feeds the bulb in the normal way. It seems to me that the bulb is activated either in the traditional manner by earthing it via the switch on the roof, or via the CCU through the purple/white wire.

Working back from from the door lock the purple/white leaves as a switched earth and enters the CCU. It exits and heads up to the rooflight and becomes an option via the switch to be the earth for the bulb.

Have you tried a multimeter taking the purple as positive and the purple/white as the negative and see what readings you get whilst locked/unlocked etc?

Hope that makes sense!!

Click to expand...

Yes! This works Thank you.

htr said:

Yes! This works Thank you.

Click to expand...

I'll inform the wife I got something right.......................

Thanks for all the input and continuing the thread. It would be great if someone could solve the riddle of the wiring as I want to put the headlining back up but can't because of my 'custom wiring job'.

TD4_4x4 said:

Thanks for all the input and continuing the thread. It would be great if someone could solve the riddle of the wiring as I want to put the headlining back up but can't because of my 'custom wiring job'.

Click to expand...

I thought we had !!!!!

Hi again.

Can someone please help me with this problem as I'm desperate now as the winter is approaching and the car trim and headlining is still stripped out.

Is there anyway someone can explain to me what I need to do in detail, or can I pay someone to come to me and do the work for me? I can't drive as I'm housebound and never leave the house.

If someone knows anyone who can fix this for me, please PM me asap.

I'm in Harrogate.

Attached is a photo to show I am genuinely stuck. The wires are a mess but aren't as scary as they look:

4 x external door handle LED.
4 x additional interior LED lamps.

All taking a single feed off original wires for roof light under the headlining. (Worked before taking headlining off). My problem is detailed in the first post on this thread on page 1. http://www.landyzone.co.uk/lz/f9/feed-off-map-light-wiring-working-backwards-263451.html

Once I've got it working, I can get the headlining on and the rest of the trim.

Many thanks for hassling everyone again and sorry for appearing useless but I am totally stuck.

Have you tried what has been suggested above? Seemed to have worked for Htr

Bit difficult to work out what's going where on the photo. However, as I recall it's straight forward enough. From the original wiring:

Purple is the positive feed

Purple/White is negative feed 1 (controlled by the CCU)

Black is negative feed 2 (controlled by the light switch)

To enable your accessories to work like the roof light when locking / unlocking etc use purple for the positive feed and purple / white for your negative feed.

I have put the led ones in my fl1. Run the live from the interior light and then earth off the purple/white coming off the door. It took a lot of trial and error to work out

or connect a relay to the light is self work for me (yes i know its a old thread )