The Mystery of the Glowing Bulbs

[jeremy996]

I treated my 1989 110 CSW to two new rear lights, holders, lenses and fancy LED stop/tail bulbs about six months ago as the previous bulb holders were completely FUBAR.

Over the last few nights I have seen the nearside rear stop/tail light emit a ghostly glow. This evening my neighbour rang to say my LRs rear lights were on and flashing. I went out and had a look and they were both on as if the lights were switched on and they randomly flashed. I've just gone out again to look and we're back to the ghostly glow.

The light switch is definitely off and switching on and off seems to make little difference. As LEDs use a much lower current to work could this be a dodgy earth somewhere else or the alternator rectifier on the way out?

Other helpful suggestions?

[l4ndymac]

I treated my 1989 110 CSW to two new rear lights, holders, lenses and fancy LED stop/tail bulbs about six months ago as the previous bulb holders were completely FUBAR.

Over the last few nights I have seen the nearside rear stop/tail light emit a ghostly glow. This evening my neighbour rang to say my LRs rear lights were on and flashing. I went out and had a look and they were both on as if the lights were switched on and they randomly flashed. I've just gone out again to look and we're back to the ghostly glow.

The light switch is definitely off and switching on and off seems to make little difference. As LEDs use a much lower current to work could this be a dodgy earth somewhere else or the alternator rectifier on the way out?

Other helpful suggestions?

Hi ,could it be a faulty brake light switch ?

[pinny]

where do you park under any high voltage cables or on top of any buried ones if there was enough radiated current from these would it cause them to light as thay only draw a tiny amount of current to illuminate ive seen it done with a fluorescent tube under hv cables just a thought or maybe im crackers

[simonb]

I treated my 1989 110 CSW to two new rear lights, holders, lenses and fancy LED stop/tail bulbs about six months ago as the previous bulb holders were completely FUBAR.

Over the last few nights I have seen the nearside rear stop/tail light emit a ghostly glow. This evening my neighbour rang to say my LRs rear lights were on and flashing. I went out and had a look and they were both on as if the lights were switched on and they randomly flashed. I've just gone out again to look and we're back to the ghostly glow.

The light switch is definitely off and switching on and off seems to make little difference. As LEDs use a much lower current to work could this be a dodgy earth somewhere else or the alternator rectifier on the way out?

Other helpful suggestions?

When they glow measure the actual volts on the connector of the lamp unit, sounds like me to be duff brake light switch. A dodgy earth wouldn't cause this. Could be a diode going in the alt but this usually shows up with a flat battery very quickly as it discharges through the alt or the charge light on/glowing. I have led stop/tail lights in mine and they don't do this...

[jeremy996]

When they glow measure the actual volts on the connector of the lamp unit, sounds like me to be duff brake light switch. A dodgy earth wouldn't cause this. Could be a diode going in the alt but this usually shows up with a flat battery very quickly as it discharges through the alt or the charge light on/glowing.

I've just spent the afternoon fiddling with the CSW and getting nowhere. I've bought and replaced the brake light switch, £18.15 from the local dealer - horrible job, and it appears to have made no difference. There is a steady 2.5v at the lampholder that fluctuates a little if I put the nearside indicators on.

If I put a conventional bulb in, I can see no unexpected glowing but if I swap the LED bulbs around the other one glows as well. If I leave out the nearside LED, the offside one glows, albeit dimmer. When the brakelight fuse blew, the LED did not glow, but when I took the wires off the brakelight switch, new or old, the LEDs still glowed.

Any suggestions where I go from here; exorcism is looking more and more likely!

[paintman]

There is clearly a live feed to the units.

Are they wired up correctly?

Have you checked the wiring from the main light switches and the switches themselves?

What happens if you disconnect the alternator? (NOT with the vehicle running!)

[LR90]

Could be a wiring fault, chafing perhaps.

Can't recall constant live to the rear though there may be one for those that choose to tow caravans. Anyway assuming (?) the wiring to the rear is stock try separating it at the block connector below the clutch cylinder and measure voltages to each of pins on the main loom side, we can then check out any showing more than a coupe of volts. And also check each pin from the rear loom side of the connector both for voltage (be really amazed if you find anything) and resistance both to earth and pin to pin (possible indication of shorting in the loom).

[western]

in the right rear corner should or maybe a single fairly thick purple wire this is a permanent 12v feed, it maybe shorting across or even connected to the rear lights circuits.

[Quagmire]

I had a similar problem on my 90 (with normal bulbs). The indicator on the drivers side glowed very faintly constantly, along with the headlight and the headlight and tail light on the same side flashed when i indicated .

In the end all i did was to remove and clean the earth for the front lights and my problem was solved. I dont know how the earth being dirty at the front end made my lights go wonky like that- i would have thought they would have just packed in completely or been very dim.

[m0bcg]

do you have a radio amateur living close by, look for aerials in the air or for wires strung out across garden .

it may be someone using a radio somewhere near you which is making the lights flicker, perhaps someone using morse code [CW] and an amplifier .

i am a radio amateur and have a radio in the landrover etc and i can make my interior light flicker when im transmitting at times .

ian

[GeoffHeritage]

This sounds as if you might have water or even salt water from road gritting in a plug or connector the water will carry enough power to light your lights.I would first try cleaning trailer socket (if fitted) then progress to any other connector that has a live feed to it.Or maybe radio interferance.

Geoff

[upnover4x4]

Had similar flt recently with lights randomly working on own accord. I ended up removing all the dodgy bullet type connectors that LR fit & replaced the with screw post terminals. Sorted out the problem.Bit of a gob but ensure good continuity & tidies up the wiring at same time.

Do you have a towing hitch outlet & aux 12volt outlet for caravan. Possible water ingress in the sockets.

[Night Train]

It is worth checking all the earth connections, including ones in the dash, as any bad earths would allow current to flow back through other parts of the circuit and eventually find their way to the lamps. The earths needn't even be obviously to do with the rear lights. Given you are using LEDs then there should be diodes in the units to ensure the correct polarity, however, your dashboard repeaters would still be filament lamps and so could still allow current to flow back down the circuits to the tail lamps.

If you have any current flow in the system then you could use this as a tracking system to figure out the current flows. Usually there would be current still flowing to clocks, alternator, alarm, etc so you can pull the connections on these in turn to isolate the suspect area of the vehicle.

[mpb]

Go into the engine bay & unplug the wiring loom on the drivers side that feeds the rear lights. This will give you an indication if its the front or rear lights are at fault.

[jeremy996]

I've just looked out of the window and the red rear lights are flashing at random like a disco - I'd guess water in the connectors as its raining hard and I've done about 90 miles today. I have a rear hitch and single electrics, so there is plenty of scope for some short circuits!

[TomG]

As Western says, there's a permanent 12v feed to the rear (in the loom going through the chassis to the rear) - mine was powered even when the key was out of the ignition, quite why Land Rover did this i don't know.

On mine, everytime i went through water the rear lights came on. The loom through the chassis was in some state, where it enters the chassis in the engine bay, the exhaust manifold had melted much of the insulation and previous chassis welding had a similar effect on the loom further back.

Ripped it out and replaced with 7-core trailer cable (soldered and heatshrinked to the existing connector), zip tied along the top of the chassis and under the bodywork, this gives enough wires for L&R indicators, tail, brake, fog and reverse lights. Worked for me

[pantherslover]

I'm having exactly the same problem.. the fog light indicator lamp glows dimly at the same time as the left hand rear tail and indicator lights glow. All my relays and fuse connections are somehow slightly corroded. It's definitely a loose wire causing this.

[Smego]

Next full moon use the glow of it to see if there is a faint figure sitting on any of the seats, as could be caused by a ghostly bogie man woo hoo,

[Snagger]

These things are usually down to a bad earth if something else is also on, but with everything else switched off, there should be no back current.  But you have LEDs, the "D" being critical - they will not work from a back current due to bad earths, so they are definitely getting power from something.  I'd try disconnecting the output from the brake light switch first, as the easiest isolation to reach but also because the front sidelights would also be drawing power if it's a fault in the tail-light rather than brake light circuit.  If it still occurs with the brake light disconnected, then disconnect the sidelight switch and see what happens.  I suspect you have a bad switch in one of those circuits which is not entirely isolating the circuit.

[jeremy996]

Just to update an old thread, my lights stopped behaving quite so badly when I waxoiled the rear chassis after a dry spell. When the rebuild commenced, it was clear that the rear wiring in the chassis members was in a poor state and the insulation was shot. 

[pantherslover]

Ok well. I've found the problem. On the counterweight side of the transfer box is an earth connection with two wires. I obviously didn't do this up properly after the tbox issue. This is the earth connection for both rear ends.  The only issue now is the trailer making the turn signal relay flash all the time when the indicators are not on. Almost there. It functions normally when the indicators are on our the hazards. All lights working ok.  Now just this pesky trailer symbol flashing. Someone had previously just disconnected the trailer to flasher relay wire. Maybe i go back to that resolution?