Lr3 Trailer lights....head explody!

Hey guys, looking for a hand here p l e a s e.

I have an 06 LR3 and hooked it up using the Atlantic British trailer harness.

I get right trailer lights, turn signal and brake lights, all good.

With the trailer plugged in, the left side trailer lights are always on, brake light style. Bright, both filaments on.
It also wont show trailer flasher or have turn signals flashing when selected.

Trailer plugged in to a new Ford Explorer show all trailer lights to be operational.

I spat three times, poured a beer on the hood, but this didnt help either.

Scoured the web, checked the harness for shorts, and have found nothing. What am I missing?

Any help would be just fantastic. My flyfishing raft is about to be broken down and put on the roof rack. I am soo over poring through this problem.

Thanks a lot

Paul
 

Dendy Jarrett

Expedition Portal Admin
Staff member
Paul:
I know this seems silly, but try working the plug back and forth a bit while plugged into the truck.
Mine had issues, and turned out all the prongs were not making contact. I since placed dielectric grease on it, and it makes contact all the time.

May or may not help, but can't hurt to troubleshoot.
D
 

UK4X4

Expedition Leader
Get out the multimeter ! Finding the flasher is pretty easy

If all works on the trailer then it's just something in the truck loom.

One thing that's always difficult is the plug diagrams is whether your looking at it from the front or rear.

The other is getting the locator in the right position and not 180 degree out.

Hopefully the trailer has real bulbs ? And not led's as the truck s can bus won't see the trailer without adding some bulbs or a resistor
 
Guys thanks for all the pointers, links and advice. I will report back what I find. Two beers and I will have the dutch courage to start crawling over it again :ar15: :Mechanic:
It is definitely in the truck. Totally strange that one light stays hot all the time when the key is turned in the ignition.
Sigh...
 

johnsoax

Adventurer
When I connect an LED trailer, the lights work fine, I just get a pulse in the taillights.

It doesn't bother me, so for the few times I tow the LED trailer, I just live with it.
 
Atlantic British aftermarket loom

Well, you are not going to believe it.....

The loom/ plug I bought relies on uneven length splices for isolation of the wires which are heat shrunk tubed together. Except the uneven length splice were a little too even. Hence the short and totally eratic fault. The two splices were touching!

What a basic electrical manufacturing mistake to make for something pretty expensive...

Thanks again for the links posted to wiring diagrams and encouragement to measure current. I am amazed a fuse did not blow.

By the way, the led pulse is the truck checking to see if you have a trailer behind it.

Thanks again for all the ideas!
 

johnsoax

Adventurer
I regularly tow three trailers, a Harbor Freight 1000lb capacity flat bed with non-led lights, a 1996 Coleman camper (about 2800lbs) with non-led lights, and the 3500 lb capacity covered trailer that I share with Dad that has the LED lights. None of them have brakes, and I haven't had trouble towing any of them near their capacities with any vehicle that I have owned...
 

UK4X4

Expedition Leader
"By the way, the led pulse is the truck checking to see if you have a trailer behind it"

to rectify this you just need two resistors on the blinker circuits

In parralel to the led lights.

If your blinking the truck does not know the trailer is there and will not engage any changes, including the parking sensors, which will annoy the hell out of you.

You can tell if things are working by the indicator lights on the dash - when you indicate direction the trailer sign will flash.

You don't need fancy box's just some of these;

http://www.amazon.co.uk/dp/B008DGB2UU/ref=pe_385721_37986871_TE_item

I bought 6 one for each circuit, then disconnected each one and found I only needed 2 to stop the flickering

You could also just add some extra lights with real bulbs but these work fine
 

zelatore

Explorer
"By the way, the led pulse is the truck checking to see if you have a trailer behind it"

to rectify this you just need two resistors on the blinker circuits

In parralel to the led lights.

I'm not questioning that this works, but I have a question.

I thought the issue with LEDs was that they presented too little load - i.e. too low a resistance.

If I remember correctly, putting the resistors in parallel would reduce the presented load/resistance even further. Did you mean to say put them in series to increase the resistance?
 

unseenone

Explorer
For what it's worth, it seems a little more complicated, this is pricey, but it outlines what is going on, and the vehicle responses. Like I say, it's expensive. The site says it gets quite hot, probably from resistors or diodes, or both. http://www.labtronx.com.au/pulsebusta-mk3.htm

On the other hand, the guy is friendly, responsive and shipping is fast.
 
Last edited:

UK4X4

Expedition Leader
Your all sort of correct !

an led has little or no resistance, so yes adding the resistor would normally reduce resistance if you had 2 in parallel- but as the led has basically nothing, your are adding resistance to the circuit.

The resistor replicates a bulb, like I said you could just add a bulb or light with standard filament bulbs in parallel too

If you put in series you will drop voltage across the resistor and would have a dim or non operative led.


pulsing, yep your right the car still sends pulses, that never stops, but the resistor takes the pulse and dissipates it and the car "see's" a trailer

the led does not now pulse and the car see's the trailer, problem solved.

In my case I only needed them on two circuits, the indicators, but as the LED for brake and lights is a sealed unit it may have resistors inside , I just can't see them.
 

UK4X4

Expedition Leader
mmmm busta 3- 297Aus dollars

or $16.70 roughly from amazon and half an hour to fit, seemingly I'm in the wrong business !

3 x 25W 6 Ohm 5% Chassis Mounted Aluminum Clad Resistor 2Pcs
Condition: New
Sold by sourcingmap
£3.55
Item Subtotal: £10.65
Delivery & Handling: £0.00



Order Total: £10.65
Selected Payment Method: Visa
 

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