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HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 11:47 am
by mikeonb4c
Here's a weird one. For some time now, the LEDs I have fitted to my front cab interior light remain glowing very faintly when they should be off. If I move the master switch to the off position when the ignition key is in (as when driving) then they go off completely. However, once I take the key out then they glow faintly in either master switch position. I have no problems with battery going flat (I have the Willinton kit fitted and can't remember if the fuse jumpers will have switched interior ligts over to lesiure battery but...). Why would such mysterious behaviour appear and what might be the cause?
Any thoughts gratefully received and thanks chums.

Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 12:25 pm
by dobby
May be worth checking the door contact switches, clean them and WD40?
Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 12:26 pm
by jaylee
The circuit could well be earthing somewhere....? (Other than where it should.) Like a dodgy door trigger not shutting off completely, or a frayed wire to said earth switch making contact with the body...??
mikeonb4c wrote:Here's a weird one. For some time now, the LEDs I have fitted to my front cab interior light remain glowing very faintly when they should be off.
If I move the master switch to the off position when the ignition key is in (as when driving) then they go off completely. However, once I take the key out then they glow faintly in either master switch position. I have no problems with battery going flat (I have the Willinton kit fitted and can't remember if the fuse jumpers will have switched interior ligts over to lesiure battery but...). Why would such mysterious behaviour appear and what might be the cause?
Any thoughts gratefully received and thanks chums.

Do you have an alarm trigger fitted to the door opening light circuit perchance...? 
Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 12:32 pm
by mikeonb4c
jaylee wrote:The circuit could well be earthing somewhere....? (Other than where it should.) Like a dodgy door trigger not shutting off completely, or a frayed wire to said earth switch making contact with the body...??
mikeonb4c wrote:Here's a weird one. For some time now, the LEDs I have fitted to my front cab interior light remain glowing very faintly when they should be off.
If I move the master switch to the off position when the ignition key is in (as when driving) then they go off completely. However, once I take the key out then they glow faintly in either master switch position. I have no problems with battery going flat (I have the Willinton kit fitted and can't remember if the fuse jumpers will have switched interior ligts over to lesiure battery but...). Why would such mysterious behaviour appear and what might be the cause?
Any thoughts gratefully received and thanks chums.

Do you have an alarm trigger fitted to the door opening light circuit perchance...? 
Nope. I keep trying to think what electrical mod I might have made that could have brought it on, but can't think of any really except perhaps the Willinton kit, whose ramifications I wouldn't understand. Its not doing any harm, but it would be nice to get to the bottom of it.
Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 12:34 pm
by helen&tony
Hi Mike
As previous reply....alternatively, I can recommend a good exorcist ...I reckon the local Orthodox priest here would scare the pants off anything just by his presence ...about 6 foot 6 tall AND wide, bearded and the funny black hat.....SCARY
Ghostly LED's ...NO Problemo
Cheers
Helen
Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 1:03 pm
by jaylee
helen&tony wrote:Hi Mike
As previous reply....alternatively,
I can recommend a good exorcist ...I reckon the local Orthodox priest here would scare the pants off anything just by his presence ...about 6 foot 6 tall AND wide, bearded and the funny black hat.....SCARY
Ghostly LED's ...NO Problemo
Cheers
Helen
Your Bongo overheats in HELL..!!!
Seriously though, i'd start looking at the light unit first, & see if one or both of your LED bulbs are seated properly...??
Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 4:47 pm
by g8dhe
If the master switch is in the OFF position then, if they really are glowing then it must be a fault within the switch unit.

The Door switches won't even be connected at that point...
However do bear in mind that LED's will reflect back out (unlike filament bulbs) any other light that is on in the cab area ?
Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 6:35 pm
by mikeonb4c
g8dhe wrote:If the master switch is in the OFF position then, if they really are glowing then it must be a fault within the switch unit.

The Door switches won't even be connected at that point...
However do bear in mind that LED's will reflect back out (unlike filament bulbs) any other light that is on in the cab area ?
Useful replies again guys and thanks. It's definitely a v small amount of electricity at work. Only a v dim glow, but its not a reflected one. I'll have to do some multimeter testing when I get a round tuit

Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 8:48 pm
by jaylee
Mike, It may not become apparent when you look at the light unit... (& i'm not sure what kind of LED set up you have in the cab lights.)
But have a look at where the bulbs go directly into the two capless bulb lamp housings... The positive & negative connectors that the bulbs plug into can get twisted & may be touching..?? Especially if its a tight fit, the metal tabs may have been pushed skew when the LED was fitted causing the weird effect....?!
Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 9:20 pm
by mikeonb4c
jaylee wrote:Mike, It may not become apparent when you look at the light unit... (& i'm not sure what kind of LED set up you have in the cab lights.)
But have a look at where the bulbs go directly into the two capless bulb lamp housings... The positive & negative connectors that the bulbs plug into can get twisted & may be touching..?? Especially if its a tight fit, the metal tabs may have been pushed skew when the LED was fitted causing the weird effect....?!
Thanks hauled, i'll check that out, though I don't think anything got forced.
Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 11:18 pm
by jaylee
mikeonb4c wrote:jaylee wrote:Mike, It may not become apparent when you look at the light unit... (& i'm not sure what kind of LED set up you have in the cab lights.)
But have a look at where the bulbs go directly into the two capless bulb lamp housings... The positive & negative connectors that the bulbs plug into can get twisted & may be touching..?? Especially if its a tight fit, the metal tabs may have been pushed skew when the LED was fitted causing the weird effect....?!
Thanks jaylee, i'll check that out, though
I don't think anything got forced.
Mike, from my experience some of these plastic cap-less fittings are a smidgen fatter than the glass filament counterparts...
I had it happen with a T5 in the light over the rear heater controls blow the dash fuse... & a rear numberplate light did some weird stuff with one of the replacement T10's....
Worth a look....!?
Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 11:52 pm
by mikeonb4c
Thanks jaylee, will do. I see a post where my predictive text called you 'hauled' is still there although I deleted it. I give up!
Re: HELP: Interior light LEDS glow faintly when off
Posted: Sun Mar 18, 2012 11:57 pm
by dreamwarrioruk
you will also find that led lamps only need a very small amount of electricity to run. Had this problem in a house. with the led switched off they still glowed very faintly. Found out that it was the light switch doing it as the contact was so close that it was acting as a capacitor. enough to keep the led glwing. try using an ordinary filiment lamp in the same circuit as the led and see if they go out.
Re: HELP: Interior light LEDS glow faintly when off
Posted: Mon Mar 19, 2012 12:35 am
by mikeonb4c
dreamwarrioruk wrote:you will also find that led lamps only need a very small amount of electricity to run. Had this problem in a house. with the led switched off they still glowed very faintly. Found out that it was the light switch doing it as the contact was so close that it was acting as a capacitor. enough to keep the led glwing. try using an ordinary filiment lamp in the same circuit as the led and see if they go out.
I think you are probably 100% spot on with this Mike. It's what I suspect, but hearing a qualified leccie say this males all the difference. I'll check it out. Good to hear from you by the way, and hope things are well with you guys.
Re: HELP: Interior light LEDS glow faintly when off
Posted: Mon Mar 19, 2012 12:36 am
by jaylee
mikeonb4c wrote:Thanks jaylee, will do. I see a post where my predictive text called you 'hauled' is still there although I deleted it. I give up!
Don't worry dude, i'm tapping this out on a 7" tablet & anything can go wrong....!
