Hi guys,
Just bought my mother’s mk1 ‘53 plate (pre facelift) TD4 3dr, which has been off the road for approx 12 months, got through MOT and when I was driving home, flashed main beam to let someone out and I heard a clicking from the boot, carried on home and did some investigating, and the headlamp switch appears to be operating various boot items, I’ll try to simplify what here;

Sidelights - one boot-opening click (doesn’t open boot, window doesn’t drop)

Dipped beam - sometimes one, sometimes loads of boot-opening click (doesn’t open boot, window doesn’t drop)

Flash mains - lots of boot-opening clicks, boot doesn’t open, window doesn’t drop

Dipped beam on, and flash/switch on mains - boot window drops fully, wiper goes on full pelt and boot door opens.

To me, this sounds like an earth fault, I’ve ran a wire from the boot door to the negative pole on the battery and still does the same. Boot door handle, always functions normally and as expected. Also the rear washer doesn’t work but I’m 99% sure that’s unrelated.

I’ve tried googling but nobody seems to have a similar problem, any help will be gladly appreciated :)
Tia, Callum
 
Ok. I can't think of any reason the light switches affect anything at the rear, other than send power to the tail light bulbs. There's no need for anything at the back to be fed from the dip or main beam.
You see that’s my thinking. I recently had an issue with my metro, where the engine kept running when my headlights were on and brake pressed, took me ages to work out it was actually led stop/tail bulbs back feeding the fuel pump. Switched back to filament bulbs and problem solved.
But I can’t see how flashers make any difference to the tailgate. Are the switches based on a hard wire system or is it can bus system?

Are there any plugs/ connectors that are close where wet might have got in?

Thanks,
Callum
 
I see what @Nodge68 is thinking.
If a dual electrics was installed there should be a 7 way relay in the boot. Maybe someone stuck one in with the idea of wiring it up later. Worth a look, most towing relays are Chinese garbage.
Mike
 
Ah right thanks, I’ll have a look, it came with the car so we never fitted it, looks like a neat ome so may have been factory. Is there a standard plug or is it piggyback stuff? I’ll try and get a look this morning.

Again thanks for both your help :)
 
Mine came with factory fitted tow bar and single electrics. When we added the second socket we found they'd put the relay in ready to use. It didn't work, and sent the lights into disco mode when we plugged the towing electrics in.
Good old land rover, quality parts used always:rolleyes:
Mike
 
Great fault ....you must post thw findings!! Just a thought. Check all rear lights work as they should. Could be loss of an earth to a light cluster and getting earth return through rear door. That could explain why earthing door makes no difference. Doesn't explain the link to headlights but could be changes in voltage on other light circuits? Also. You are thinking about false feeds. Don't rule out voltage drop die to a short. My rear wondow drops when I dis and reconnect battery. Good luck.
 
Mine came with factory fitted tow bar and single electrics. When we added the second socket we found they'd put the relay in ready to use. It didn't work, and sent the lights into disco mode when we plugged the towing electrics in.
Good old land rover, quality parts used always:rolleyes:
Mike

Ah right, superior quality where abouts is the socket? Near the OSR lamp?

Great fault ....you must post thw findings!! Just a thought. Check all rear lights work as they should. Could be loss of an earth to a light cluster and getting earth return through rear door. That could explain why earthing door makes no difference. Doesn't explain the link to headlights but could be changes in voltage on other light circuits? Also. You are thinking about false feeds. Don't rule out voltage drop die to a short. My rear wondow drops when I dis and reconnect battery. Good luck.

Don’t worry I will :) like I say I’ve been googling but found nothing. It’s just passed MOT but I’ll admit I never checked them. I’ll get all the lamp covers off and see if anything looks amiss

Again tanks a lot,
Callum
 
The socket for the tow bar electrics is behind the OS rear boot trim, just below and forward of the boot light. You have to remove the boot trim panel to get at it.

Great thanks, providing weather has a break for 10 mins I’ll get a look this morning, if not tomorrow morning is supposed to be dry I’ll have a snoop then :)

Again thanks very much for everybody’s help :)
P.S, if anybody would like a video of what it’s doing, I have one but it won’t upload, so I’ll try and link it to g drive so you can see :)
 
image.jpeg
Ah right thanks, I’ll have a look, it came with the car so we never fitted it, looks like a neat ome so may have been factory. Is there a standard plug or is it piggyback stuff? I’ll try and get a look this morning.

Again thanks for both your help :)
You will also need a towing relay. This lights up a little green trailer on the dash when you indicate to show that all is well with the light set up. I got mine out of an old Freelander at the scrappies that had a tow bar fitted.
 
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Right, I promised you an update, and I’ve got one XD

I took the lens covers off all the back lamps, and found nothing untoward. So I checked the fronts and found nothing either. I found a lot of wettness in the rear tailgate; along with rusty screw clips and body corrosion near the door handle, so probably will require a new tailgate at some point. I then started unplugging things and seeing if the fault re-occurred. Eventually I found that unplugging the 6 pin plug for the O/S/F headlamp unit resulted in all faults disappearing. Plugging back in caused faults to re - occur.

Having done a very “bodge” job of re earthing the headlamp, (consisting of a wire from the bulb to the battery....) pluging the lamp back in again, all faults disappear, and lamps working correctly. I’ll take the loom apart over the next few days, along with sourcing a few new parts.


**other people with this or similar faults**
If switching on electronics works systems it shouldn’t, unplug “correct” systems (in my case lamps) and work the switches. If faults re-occur go to the next one. And try re earthing. Good luck :)

FYI for anybody interested, it’s this plug (below). Thanks very much to everybody for your help. Really appreciate it :)

23F092AD-8C41-4C22-8503-C60DAA0319EE.jpeg
 
So loss of earth to lamp cluster ! Is that the plug to the headlight height adjustment, trying to work out why it would affect the back door ??
CCU control perhaps?? Anyone know whether these functions all go through the CCU?? Just interested and we can learn more about the mystery black boxes !
 
So loss of earth to lamp cluster ! Is that the plug to the headlight height adjustment, trying to work out why it would affect the back door ??
CCU control perhaps?? Anyone know whether these functions all go through the CCU?? Just interested and we can learn more about the mystery black boxes !

The CCU does connect to the headlights as some markes require the dip beams on when the engine is running.
 
It’s the big multi plug to the whole lamp unit, 6 pin I think, re earth of the 3 pin plug for the H4 headlamp bulb (on the bulb itself) resolves all issues. So I’m going to try to go back into the loom to try to find the break or poor earth
 

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