Trailer detection problem

[wbowner]

Hi
I have 2014 D4

i have one of those linear design led modules hardwired in

it has worked ok since car new


Normslly when this is on and you use an indicator a green trailer flashes on the console
At the moment this is only happening for the left indicator

the result of this is that the right indicator on my van is not working. I have not been able to test the van does work but do suspect the car as per following test

no van connectef
turn on led module
left indicator see green trailer
rught indicator see nothing

any ideas


thsnks for any help

Richard

(I thought I posted this earlier but could not find it)

[IndusD4]

I played with making one of those boxes myself which puts a resistor in parallel with at least one of the indicators. Doesn't have to be both. However if you only put the resistor on one of the indicator circuits, you'd need to use that indicator before the car recognises the trailer (the green light lights up). From then on, whichever indicator you use you see the trailer indicator confirmation light.

I'm not sure if what you say is that the light on the trailer doesn't work at all (and the green light on the dash doesn't either), or the green light doesn't come on after starting the car and using the right indicator first.

In the first case, I'd be checking the trailer light as the resistor is in parallel so wouldn't be the cause of the indicator not working.
In the second case, does the right indicator light on the trailer (and in the car) work after using the left indicator first?

Ron

[wbowner]

Ron
The green cart light does not come on when indicating right only left.

just tested again and it did, not sure what is going on

i am testing without van attached

when van attached no right indicator light

Richard

[kenl]

On my car (2011 d4) the trailer is not found by the car unless you open and close a car door while the car is NOT running, you will see it flash the trailer lights when you do this.

If I connect a trailer while the engine is running and hop in and drive it will not see the trailer until I stop the engine and open and close a door.

Those linear design modules should have a lifetime warranty on them, for what they cost!

[IndusD4]

You'd think that there is a loose connection in the Linear design box, probably at the point where the resistor is connected - If the resistor was still connected you'd get a green light on the dash, and if the wire to the lights/plug isn't connected you wouldn't have an indicator light on the trailer. As you say you have neither, I'd think it is a connection that's loose. Can you access the box and open it up?

Ron

[wbowner]

I don’t think it is a problem with the van but would like to test it
I was going to make a tester but am on the road so can’t

The fact that some times it works and sometimes not smacks of a loose wire and difficult to diagnose

in in the past the green cart would go on when either indicator is turned on if the led gadget is turned on

I also found you need to turn it on before starting the motor as well.

i also found that if you didn’t turn the led gadget on then both van indicators would flash.

Richard

[SBD4]

Ron
The green cart light does not come on when indicating right only left.


If I remember rightly, I think this is by design to indicate you have a blown light on the trailer (the old globes). Given you have LEDs it would indicate a wiring issue on the right circuit.

Get a volt meter and trace the issue. Have you tried the trailer on another car?


....when van attached no right indicator light ....

By this I assume you mean the trailer has no right blinker, while the D4 does.

BTW (I'm sure you know this) the D4 does not need the linear electronics box, all that is required is a couple of resistors in parallel with the trailer blinkers - you only need one but for the price, I would do one on each blinker. So if its the box then you have a cheap fix.

[wbowner]

Sean
Haven’t tried van on another car

I would like to do this but don’t know any one here. My van has a 12pin flat plug.
I have been thinking of just buying a 12 pin receiver and wire up a 12 v plug to pin 1 and 4 and put a cigarette lighter plug at the other end to see. Would that work?

Richard

[IndusD4]

Hi Richard,

If you have a multi-meter you could just check if there is a voltage on those pins at the plug on the car?

Ron

[wbowner]

I have and did but the reading was bouncing all over the place on left side

The right seemed to confirm my feeling it is a car
The thing I was thinking of making was for the van to make sure it’s lights were working ok

Richard

[SBD4]

I have and did but the reading was bouncing all over the place on left side

The right seemed to confirm my feeling it is a car
The thing I was thinking of making was for the van to make sure it’s lights were working ok

Richard
hi Richard, if everything is fine with the car itself indicator-wise then you need to work back from there. check the signals going into the LE box and coming out. Make sure you do it at the actual inputs outputs on the box, not at some other location. Ideally, you would remove the box and see what happens then, that's the easiest way to rule the box in or out as being the problem.