Sirocco Posted February 9, 2012 Share Posted February 9, 2012 Afternoon Gents, We connecting my trailer up to my 90 the rear tail lights on the vehicle do not work. Now, the 90 and trailer are all using conventional bulbs bar the rear tail/brake lights which are LED. Brake lights work, but tail does not when connected to the trailer. Swapped out the bulbs for conventional ones and it all works fine. So, why do the LED bulbs do this? and what can I do to make them work with my trailer? I need the LED ones as conventional red bulbs turn pink after not long. They are also a lot brighter. any help appreciated. G Quote Link to comment Share on other sites More sharing options...
mmgemini Posted February 9, 2012 Share Posted February 9, 2012 How old are the LED's ? Some of the older LED's were polarity concious...... Some Defenders are wired up not following convention. Check that the wiring to the tails are correct. Quote Link to comment Share on other sites More sharing options...
Sirocco Posted February 9, 2012 Author Share Posted February 9, 2012 How old are the LED's ? Some of the older LED's were polarity concious...... Some Defenders are wired up not following convention. Check that the wiring to the tails are correct. Not that old <12 months. The wiring must be correct because it works with normal bulbs. Have spoken to someone and they think I need to add a ballast to the 90 wiring. MAy fit LED's to the trailer and see if that solves it. G Quote Link to comment Share on other sites More sharing options...
mmgemini Posted February 9, 2012 Share Posted February 9, 2012 Yes I see said the blind man..... Try the LED's on the trailer with LED's in the 90 and see what happens. Could you let me know please. There's an article on Caravan and Outdoor Life magazine this month about LED's being fitted to caravans and causing vehicle problems. I haven't read it yet though. It's a South African mag Quote Link to comment Share on other sites More sharing options...
UdderlyOffroad Posted February 9, 2012 Share Posted February 9, 2012 (edited) Have spoken to someone and they think I need to add a ballast to the 90 wiring. MAy fit LED's to the trailer and see if that solves it. G I think you’re getting the two common issues with LED lighting confused. You need to add ballasts to indicators, in order that they don’t flash too fast. Reason being, flasher relays are required to have a bulb failure indication function. They do this by sensing load (current) drawn by the indicator bulbs. If one is blown, the current will be lower, and the relay will make the remaining bulbs flash faster. LED lights, because of their lower current draw, tend to cause the relay to flash too fast, hence the need to fool the relay by adding ballasts (the other option is to swap the flasher relay for LED-compatible one). This lower current draw/ballast requirement isn’t usually an issue with any other lights other than indicators. The other issue with LEDs is that they are Light Emitting Diodes. The diode part is important, in that they can only be wired one way or they won’t work…my guess would be that the wiring in your trailer is stop/tail socket is wired backwards. So what would normally be +ve is wired to -ve With bulbs this would make no difference. A multimeter with a continuity buzzer should help you diagnose this, and workout where you need to swap the wires over. As mmgemini says, it’s not unknown for Defenders to be wired up ‘backwards’ too. Edit to add: better explanation of why you need a ballast with LED Edited February 9, 2012 by UdderlyOffroad Quote Link to comment Share on other sites More sharing options...
GBMUD Posted February 9, 2012 Share Posted February 9, 2012 I know it is no help, but when I first wired that trailer it all worked perfectly with incandescent bulbs, so unless the trailer wiring has been interfered with, it can be assumed to be OK. Chris Quote Link to comment Share on other sites More sharing options...
mmgemini Posted February 9, 2012 Share Posted February 9, 2012 I understood that LED's are no longer polarity consious. The last ones I bought a couple of years ago certainly are not. Different supplier maybe ??? Quote Link to comment Share on other sites More sharing options...
landroversforever Posted February 9, 2012 Share Posted February 9, 2012 A bulb will work either way round, an LED will not, swap the wires and see what happens Quote Link to comment Share on other sites More sharing options...
landroversforever Posted February 9, 2012 Share Posted February 9, 2012 I understood that LED's are no longer polarity consious. The last ones I bought a couple of years ago certainly are not. Different supplier maybe ??? Unless something has changed, and LED is a Light Emitting Diode, the very nature of a diode is that it only passes through one way. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted February 9, 2012 Share Posted February 9, 2012 Unless something has changed, and LED is a Light Emitting Diode, the very nature of a diode is that it only passes through one way. The information I have was given by my supplier was that they LED's are no longer polariy consious. I can only say what information I've been given. I've only use LED's since 2004 and I know the first LED's I fitted were polarity consious. One of the problems with the lights fitted into the 200/ 300Tdi make it difficult for people to fit the wires correctly. Anyway you shouldn't be fitting LED's into any lamps into vehicle lights. They are not legal. Quote Link to comment Share on other sites More sharing options...
SORNagain Posted February 9, 2012 Share Posted February 9, 2012 Newer LED's may have some doides included which always steer the current through the LED in the correct direction. Some do, some don't. Quote Link to comment Share on other sites More sharing options...
UdderlyOffroad Posted February 9, 2012 Share Posted February 9, 2012 I know it is no help, but when I first wired that trailer it all worked perfectly with incandescent bulbs, so unless the trailer wiring has been interfered with, it can be assumed to be OK. Chris Not true: The other issue with LEDs is that they are Light Emitting Diodes. The diode part is important, in that they can only be wired one way or they won’t work…my guess would be that the wiring in your trailer is stop/tail socket is wired backwards. So what would normally be +ve is wired to -ve With bulbs this would make no difference. In other words, your trailer could be working perfectly with bulbs (as the OP describes) but wouldn't work with LEDs because the socket within the lamp might be connected backwards. The information I have was given by my supplier was that they LED's are no longer polariy consious. I can only say what information I've been given. I've only use LED's since 2004 and I know the first LED's I fitted were polarity consious. One of the problems with the lights fitted into the 200/ 300Tdi make it difficult for people to fit the wires correctly. Whilst LEDs themselves are, by definition, polarity concious, LED lamps might not be - they might have two LEDs wired in opposite directions - so they work whichever way they're connected: Anyway you shouldn't be fitting LED's into any lamps into vehicle lights. They are not legal. The newer-style NAS Lamps are now 'E' marked, such as these Quote Link to comment Share on other sites More sharing options...
mmgemini Posted February 9, 2012 Share Posted February 9, 2012 I have a GU 10 LED in my house. It doesn't matter which way round you fit it to the socket. I have some double pole 12V LED's what work anyway round I have some MR16 LED's which work anyway round. Come over and I'll shew you them all. You can move the wires yourself VOSA told me that you may not retro fit an LED to a light. It is illegal.They are checking that as part of the MOT now. A new complete LED light, as opposed to a lamp. {What you call a bulb. The bulb is just the glass on the lamp}. Is legal as is the one in the link from Chris. Now this isn't sorting out why the damned trailer lights aren't working. Quote Link to comment Share on other sites More sharing options...
Sirocco Posted February 9, 2012 Author Share Posted February 9, 2012 haha, what happened here while I went to my Russian evening class? Chris - The trailer lights work fine. Its only when connected to my 90 that the 90s stop/tail does not work. The brake part does, just not the tail. I know it is the LED bulbs because when I replace them with normal all works fine again. The pins on the LED bulbs are stepped so only fit the holder one way which all works fine when no trailer connected. It has to be something to do with the resistance surely? G Quote Link to comment Share on other sites More sharing options...
GBMUD Posted February 10, 2012 Share Posted February 10, 2012 One thought, if there was an earthing fault with the trailer electrics, either in the trailer OR the car, then you might get odd results - rather like a Ford Orion where the rear lamps turn to disco lights when the brake and indicator are on together. Chris Quote Link to comment Share on other sites More sharing options...
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