Thread: trailer wiring

I'll move this to the D3 section guys.

Originally Posted by boardrider

mr lr.
thanks for that.
that is now my next step,try with normal lights.
yes all the lights work fine,just the car is not recognising a trailer.as i have said both my trailers have led lights,now i need to find the right trailer to try on .if it is the car any suggestions where to look as the auto elec cant work it out to date
boardrider

Hi Boardrider,

The question is why do you need the car to detect the trailer ?? Does this activate trailer stability ? If you help me understand why you need it, I can design something to activate it.

The reason why it is not being detected is resistance - or more precisely current draw. LEDs are very power efficient and draw a fraction of the current drawn by normal bulbs. So one solution is for you to put a normal bulb in the circuit used to detect the trailer.

There is a CD with all of the service manuals for LR up to D3 on ebay $30 I think. If you buy it and send it to me, I will send it back, I can look at the wiring diagrams and tell you what you have to do.

If you don't add a bulb, you can add a resistor to draw enough current to trigger the detection device. Its quiet simple to solve.

Gippslander in this thread gave you the answer as he has one trailer with LED & another with bulbs. The bulbs one works, but why do you need the little light on the dash to tell you, that you have a trailer in the back ? am I missing something ?

Regards
Tor

If you search the forum you will find lots of info on trailers and LED lights.

The D3 needs more than just resistors as it sends a pulse out regularly to check if the trailer is connected. This causes the LED indicator lights on the trailer to pulse even if a resistor is fitted. To get around it a relay is fitted which isn't energised by the pulses but is energised when the indicators operate, a resistor also needs to be fitted to fool the ECU into thinking a load is connected, when this is done correctly the trailer (green) light will flash on the dash when you use the indicators. The dash light does not operate at any other time.

Originally Posted by Geedublya

If you search the forum you will find lots of info on trailers and LED lights.

The D3 needs more than just resistors as it sends a pulse out regularly to check if the trailer is connected. This causes the LED indicator lights on the trailer to pulse even if a resistor is fitted. To get around it a relay is fitted which isn't energised by the pulses but is energised when the indicators operate, a resistor also needs to be fitted to fool the ECU into thinking a load is connected, when this is done correctly the trailer (green) light will flash on the dash when you use the indicators. The dash light does not operate at any other time.

You seem to know - why do you need the light on the dash to tell you, you have a trailer ?? Does the LR do something different when it detects the trailer??

as he said -- -- try this link http://www.labtronx.com.au/pulsebusta-mk3.htm

It seems like a pretty important addition to a LED based trailer

Quote:
The rear parking aid sensors can be disabled as well as the vehicle’s rear fog and reversing lights in order to eliminate reflected glare from the front of a trailer.
The Body Computer can communicate its trailer recognition to the following:
Suspension – at highway speeds automatic changes to ride height can be disabled to reduce the possibility of directional instability in the vehicle and trailer.
Anti-Lock Brakes, Stability and Traction Control – when in motion alternate strategies can be applied to control the dynamics of the vehicle and trailer.
Power Train Control – engine fuelling, throttle response, automatic transmission shift points, enhanced dynamic engine braking, etc. for the vehicle.
Trailer lighting –turn signals, park and/or brake LEDs on the trailer that were continuously blinking will no longer do so.

Tor

Turns off the reverse parking sensors and other things such as trailer stability and things like that in later models. Also the light tells you that the trailer indicators are working.

Found the circuit - as others have said the information is in the Forum, circuit and all. Pretty cheap to make.

Option 1) add it to each trailer
Option 2) in line plug-in
Option 3) Switchable unit at rear of car

parts should be approx 30 to $40.
Resistors at $10ea http://www.ebay.com/itm/12v-load-Res...629fbd&vxp=mtr


Q & A:
1) Does this happens to the D4? - Answer: you get no pulsing as disc has LED tails, but trailer detection is an issue. so needed.
2) Resistance & wattage values of the resistors needed ? Answer: Most people use : 6 ohm, 50 Watt - some suggestions of 8 ohm being used this would reduce the heat.
2a) I will try and find out what the highest Ohm is acceptable - to reduce heat dissipation and need for heat sinks.
3) It sends pulses down both turn indicator circuits - I guess redundancy, in case one of the turn bulbs blow.

Cheers
Tor

Yes this is an issue on the D4 though, not to the same extent as the D3. D4 issue can be solved by a resistor in parallel with the blinker circuits to provide the appropriate load.

PS Tor, there are solutions already provided for both vehicles.

Originally Posted by SBD4

Yes this is an issue on the D4 though, not to the same extent as the D3. D4 issue can be solved by a resistor in parallel with the blinker circuits to provide the appropriate load.

PS Tor, there are solutions already provided for both vehicles.

Yes - thank you I have been reading up on the HUGE thread - this has caused some trouble for people - lol