LED Trailer/Caravan Lights

[Keith Hart]

Hello

My vehicle is a 2011 Barbarian, which of course has 'normal' bulbs. I tow a caravan and have just changed it for a new model (Swift Challenger 635) which has LED rear lights/indicators/brake lights fitted. The 'old' caravan had 'normal' bulbs.

When hitched up the new caravan indicators intermittently flashed very quickly or occasionally at the normal speed. I understand that this is because the LEDs are low wattage and the truck thinks that the indicators are not working!

I am currently sorting out an electronic device which is fitted to the caravan electrics that 'fools' the truck into thinking that the LEDs are 'bulbs' and therefore they flash correctly. The manufacturers, Sargent Electronics, did tell me that they had not sent one of the units out for an L200 and they could not be sure that the one they sent would work (VLM Unit A3) and that if it did not they would swap it for another specification unit (VLM A4).

Unfortunately the VLM A3 didn't work, so it is on the way back for them to swap.

I was wondering if anyone else had this problem, and if so how was it cured? Is there some modification that can be done to the truck?

Thanks.

KH

[suffolk yokel]

"Traditional" flasher units were a thermo-mechanical device - some of the current flowing to the lamp was diverted through a resistor to heat a bimetalic strip which caused a contact to move and break the current to the lamp, Then the bimetal strip cooled down, re-established the current turning the light on and the cycle started again. The rate at which they flashed depended on the wattage of the bulbs, the lower the watts the lower the current the lamp took and the faster the strip heated up and cooled down. Hence no lamp caused rapid flashing.

I suspect all your commercial device does is wire a resistor in parallel with the LED in the caravan so the device in the truck thinks it is feeding a higher wattage lamp. You get the long life of the LED with none of the power saving but it's no worse for the environment if you ignore the energy used to make the LEDs and the new "flasher ballast". At least you wont be replacing blown tail lamps every few years.

Modifying the truck wiring would mean fitting resistors between each of the wires feeding to the right and left indicator pins on the trailer connector but this would cause problems if you tow something that doesn't have LEDs, each indicator would be drawing twice as much current and you might trip a fuse in the truck.

Probably best to let the manufacturers of the VLM Unit sort out the calculations for you! Good luck.

[Keith Hart]

Well the new VLM4 didn't turn up so I telephoned to see if it was on the way - it wasn't! 

I spoke to a tech guy who said it was best to try a VLM6, which I am assured will be sent today.

I have also seen on a caravan forum that a PCT ZR2500 fitted to the L200 should work.

I have also been advised to contact Mitsubishi and ask them about a solution for a 'normal bulb' L200 to a 'LED lighted trailer'.

So, any comments on the above please and does anyone have contact details for Mitsubishi UK technical department?

Cheers

KH

[suffolk yokel]

Just looked at the spec for the VLM6. That big fan shown in the picture must be to cool some resistive load fitted inside, I suspect they simulate the resistors of the old filament bulbs so that the towcar thinks it's switching bulbs with high heat dissipation while the LEDs in the trailer just pick up a small amount of power from the normal trailer connections.

Cant tell how the PCT ZR2500 works from the spec sheet but it does say that it draws a small current from the cars lighting system to activate the trailers lights directly from the battery. If this means it doesn't draw a significant amount of current through the flasher unit you'll still have your original problem of rapid flashing.

Contact the manufacturers of both units before you spend any money.

[Keith Hart]

Hello,

The VLM6 unit is paid for and on it's way to me now. Fingers crossed it will do the job, Sargent's tech guy recommended it. If not then I'll try the PCTZR2500. I have emailed the company and asked them about using it on my L200. I'll post any reply.

I know that I'm not the only caravan tugger this is happening to and I'm sure that I'm not the only L200 owner with this problem.

As I said, I will report back so that anyone else on this forum can benefit from what I find out - good or bad!

Thanks.

KH

[Keith Hart]

Update:

The VLM6 with C44 fuse-board arrived. It was a VERY simple swap, the 'old' unit unscrews (4 screws) and the plugs are a direct swap. All the plugs are colour coded and can only fit in the appropriate socket the correct way - brilliant.

I'm very pleased to say that everything worked perfectly.   

I spoke to a tech guy at Towsure about the PCTZR2500 and he advised me that it would have done the job. The only 'extra' being that the 'alarm' would have needed extending into the cab so the driver could hear it.

So, all sorted and off with the caravan in a couple of days time.

Thanks all.

KH