A Warning About Led Lights On Caravans ...

[irie]

We recently bought a new '09 Lunar Clubman EB which we tow with a '07 Mitsubishi L200 Dual Cab Animal pickup truck.

 

We found that the bulb failure warning system in the L200 was incompatible with the LED tail lights (Hella) on the EB. This showed itself as lights showing when they shouldn't have (both indicators coming on, for example), and the bulb warning system making a 'buzz' every time the brake pedal was depressed (saying that a bulb had blown).

 

At the end of an 'interesting' <ahem> detection trail Chichester Caravans in Winchester, who we bought the EB from, fitted a modification to the EB which solved the problem.

 

This problem is known to Hella, the supplier of the LED light units. It is known to be a problem with certain Mitsubishi, BMW, and Mercedes, and probably others too.

 

So if your tow vehicle has problems with your new 'van, or your old 'van has LED light and you have a new tow vehicle has problems with the old 'van, there is a solution.

 

Thanks Chichester Caravans, you're top people.

Edited March 28, 2009 by irie

[beejay]

We recently bought a new '09 Lunar Clubman EB which we tow with a '06 Mitsubishi L200 Dual Cab Animal pickup truck.

 

We found that the bulb failure warning system in the L200 was incompatible with the LED tail lights (Hella) on the EB. This showed itself as lights showing when they shouldn't have (both indicators coming on, for example), and the bulb warning system making a 'buzz' every time the brake pedal was depressed (saying that a bulb had blown).

 

At the end of an 'interesting' <ahem> detection trail Chichester Caravans in Winchester, who we bought the EB from, fitted a modification to the EB which solved the problem.

 

This problem is known to Hella, the supplier of the LED light units. It is known to be a problem with certain Mitsubishi, BMW, and Mercedes, and probably others too.

 

So if your tow vehicle has problems with your new 'van, or your old 'van has LED light and you have a new tow vehicle has problems with the old 'van, there is a solution.

 

Thanks Chichester Caravans, you're top people.

 

Is this because the LED lamps take far less current (amps) than the conventional filament bulbs? Bulb failure warnings often rely on the drop in current when a filament bulb "blows". If so, surprised that Hella equpment causes problems. Fix probably adds a resistance in circuit to fool sensor eliminating one advantage of LEDs, low current consumption.

[irie]

Is this because the LED lamps take far less current (amps) than the conventional filament bulbs?

 

Answer: Yes

 

Bulb failure warnings often rely on the drop in current when a filament bulb "blows". If so, surprised that Hella equpment causes problems. Fix probably adds a resistance in circuit to fool sensor eliminating one advantage of LEDs, low current consumption.

 

Answer: Yes, it's a box of tricks which does exactly that.

Edited March 28, 2009 by irie

[RogerL]

I'd want to know exactly how the "box of tricks" works - it's easy to get round part of this problem by adding a resistor to each lamp circuit so that it'll draw more current but without clever circuitry in the "box of tricks" the resistor will still draw current even when the bulb has failed or become disconnected - so bulb-failure detection may not happen !!

 

Whilst LEDs are used internally to reduce current consumption, their main purpose for road lights is much better reliability as their service life is longer and even then the multiple LEDs means that one or two failed won't stop the complete lamp being visible.

[irie]

I'd want to know exactly how the "box of tricks" works - it's easy to get round part of this problem by adding a resistor to each lamp circuit so that it'll draw more current but without clever circuitry in the "box of tricks" the resistor will still draw current even when the bulb has failed or become disconnected - so bulb-failure detection may not happen !!

 

Whilst LEDs are used internally to reduce current consumption, their main purpose for road lights is much better reliability as their service life is longer and even then the multiple LEDs means that one or two failed won't stop the complete lamp being visible.

 

As you say, LED lights are much more reliable than incandescent lamps and there are also multiple LEDs in place of one incandescent lamp thus one LED failure won't stop the complete lamp being visible.

 

So if the bulb failure warning system was hypothetically compromised in the trailing device, why would it matter?

[RogerL]

As you say, LED lights are much more reliable than incandescent lamps and there are also multiple LEDs in place of one incandescent lamp thus one LED failure won't stop the complete lamp being visible.

 

So if the bulb failure warning system was hypothetically compromised in the trailing device, why would it matter?

It matters if the failure is in the trailer wiring !!

[irie]

It matters if the failure is in the trailer wiring !!

 

If the wiring is working correctly to start with then why should the wiring be any more likely to fail than with standard lights?

[RogerL]

If the wiring is working correctly to start with then why should the wiring be any more likely to fail than with standard lights?

It wouldn't be any more likely - but if the wiring fails with conventional trailer bulbs the bulb failure circuitry (where fitted) will detect the failure - if the wiring fails with LEDs, without a resistor, the failure won't be detected and the driver thus mis-informed.

[aaman]

I am planning to replace almost all of the regular bulbs in our 'van with LED's. I am not 100% convinced that the thin wiring used on Nissans (and most other Japanese cars) will be fully able to handle the extra wattage that the caravan lights will need. Each tail lamp wiring is only really designed to power one five watt bulb continuously and with the extra load imposed by the van this will more than double the load.

I plan to leave the indicators alone, they are not on for any serious length of time and I won't need to fit resistors in parallel to allow the warning buzzer to operate.

[iancwilx]

Slightly off topic.

This query relates to a non towing situation.

 

I have BMW 5 Series and it recently flashed up on the dash that I had a rear light failure.

 

I've checked all the lights and they are all working perfectly in situ.

I have checked the bulbs individually with a circuit tester and they are all fine.

 

The dashboard warning light comes on everytime I switch on the ignition accompanied by an audible "Bong"

It's really getting on my nerves !!!!!!!!!

 

Can any of you guys save my sanity ??

 

- Wilkie

[RogerL]

I am planning to replace almost all of the regular bulbs in our 'van with LED's. I am not 100% convinced that the thin wiring used on Nissans (and most other Japanese cars) will be fully able to handle the extra wattage that the caravan lights will need. Each tail lamp wiring is only really designed to power one five watt bulb continuously and with the extra load imposed by the van this will more than double the load.

I plan to leave the indicators alone, they are not on for any serious length of time and I won't need to fit resistors in parallel to allow the warning buzzer to operate.

Are you replacing the roadlight bulbs with LEDs or using the same fitting? The purpose-designed LED road lights for cars, buses etc have many more LEDs than the internal-type LED alternatives.

[seeyoujimmy]

quote[i have BMW 5 Series and it recently flashed up on the dash that I had a rear light failure.

 

I've checked all the lights and they are all working perfectly in situ.

I have checked the bulbs individually with a circuit tester and they are all fine.]

 

 

On a Merc it's commonly the number plate lamps that cause this fault.

Edited March 30, 2009 by seeyoujimmy

[aaman]

Are you replacing the roadlight bulbs with LEDs or using the same fitting? The purpose-designed LED road lights for cars, buses etc have many more LEDs than the internal-type LED alternatives.

 

I'm replacing just the bulbs, I've done it before on a previous car (pimped my ride). I know what the pin configurations are for each bulb, I just need to ensure the diameter of the lamp, not the bayonet fitting, is not too large.

[RogerL]

I'm replacing just the bulbs, I've done it before on a previous car (pimped my ride). I know what the pin configurations are for each bulb, I just need to ensure the diameter of the lamp, not the bayonet fitting, is not too large.

It's probably illegal then, as the bulbs won't be E-marked and will be lower light output in some cases.

 

Why? I doubt the reduced energy consumption will be measurable in your towcar's fuel connsumption.

[aaman]

It's probably illegal then, as the bulbs won't be E-marked and will be lower light output in some cases.

 

Why? I doubt the reduced energy consumption will be measurable in your towcar's fuel connsumption.

 

It's not the fuel consumption I'm thinking about. It's the extra load on the thin OE wiring harness in the car.

 

I had some fitted to my last car and it passed two MOT's without any comment from the tester.

Edited March 30, 2009 by aaman

[beejay]

It's not the fuel consumption I'm thinking about. It's the extra load on the thin OE wiring harness in the car.

 

Wiring has changed in the last few years. Thinner insulation for a start called "thin wall cable" carrying higher current size for size. . Canbus systems relay signalling on thin wires.

[aaman]

Wiring has changed in the last few years. Thinner insulation for a start called "thin wall cable" carrying higher current size for size. . Canbus systems relay signalling on thin wires.

 

It's not thin wall cable its thin conductor. Typicalof all Japanese cars and neither is it canbus.

[RogerL]

It's not thin wall cable its thin conductor. Typicalof all Japanese cars and neither is it canbus.

Although it's more expensive, it's a good reason for using a 7-way relay for the road lights with an 20A cable to supply the power for it.

[aaman]

Although it's more expensive, it's a good reason for using a 7-way relay for the road lights with an 20A cable to supply the power for it.

 

I see where youre coming from and have thought about it but I think my way is easier and less time consuming. I'll probably have it done in 1/2 an hour, It'll take me longer than that to feed the extra cable through the car.

[RogerL]

I see where youre coming from and have thought about it but I think my way is easier and less time consuming. I'll probably have it done in 1/2 an hour, It'll take me longer than that to feed the extra cable through the car.

All the Vauxhalls I've had, and the Subaru, have a fused power supply already built to the 9-pin trailer connector hidden beneath the boot trim which I simply used to power the relay for the roadlights.

[Watson(JohnG)]

I am planning to replace almost all of the regular bulbs in our 'van with LED's. I am not 100% convinced that the thin wiring used on Nissans (and most other Japanese cars) will be fully able to handle the extra wattage that the caravan lights will need. Each tail lamp wiring is only really designed to power one five watt bulb continuously and with the extra load imposed by the van this will more than double the load.

I plan to leave the indicators alone, they are not on for any serious length of time and I won't need to fit resistors in parallel to allow the warning buzzer to operate.

 

I have had 4 Nissan Xts and no problem with the car wiring at all

Replacing the caravan interior lights with LEDs won't have any effect on the car wiring even if you use it via the 12S soceket as the wiring to the socket will be after market and should be direct off the battery via relays

As to the tail lights etc I have had no problems and some tows have been hundreds of miles when going to Spain

The only wiring problem has been the fridge centre pin earth return melting on the 12S but there is a mod for that using spare pins

I have fitted extra running/side flashers on the caravan but power them from the fridge circuit via relay that is triggered by the flashers

If you are concerned about the load on the car wiring you could put a relay in the same way that is powered from the fridge/charger circuit and triggered by the car road light,stop light etc

But as stated earlier the Nissan wiring is up to the job