D4 not detecting trailer wiring

Just a note on the resistor units from FoMoCo, they don't work on a D4.
Ordered one and tried it, no luck.
Opened it up and found the resistors are 120 Ohms, nowhere near enough load for the D4 to detect a trailer connected.


Got a couple of Narva 21 watt resistors and rebuilt the adapter, it now works fine


https://www.aulro.com/afvb/images/im...015/01/655.jpg

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Originally Posted by jwb300

That is exactly what I have done but I'm not sure if doing this enables all of the towing functions?

Surely someone has invented an adaptor that contains two resistors so that you don't have to install resistors on all of your trailers.

Cheers,
JWB300

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I used two Narva LED resistors and made my own adaptor. Plugs into D4, resistor box sits on trailer, the trailer plug plugs into adaptor. Works a treat. https://www.aulro.com/afvb/images/im...016/06/138.jpghttps://www.aulro.com/afvb/images/im...2015/12/13.jpg

I recall seeing a post here that said the problem was not an issue on a 14MY or later. I can't find it.
I'm ordering a new boat trailer and would consider requesting the manufacturer not put the standard LED lights on it if it is going to cause hassles. Frankly I can't see any advantage of LEDs on a trailer of any sort. I doubt power savings would be an issue as you would generally have the engine running with the lights on.

Quote:

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Originally Posted by Boggs

I recall seeing a post here that said the problem was not an issue on a 14MY or later. I can't find it.
I'm ordering a new boat trailer and would consider requesting the manufacturer not put the standard LED lights on it if it is going to cause hassles. Frankly I can't see any advantage of LEDs on a trailer of any sort. I doubt power savings would be an issue as you would generally have the engine running with the lights on.

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Hey Boggs,

The way I understand it is the LED lights on your trailer won't pulse anymore (like they did previously), however the Discovery still won't know there is a trailer attached. So:

* Rear sensors will go off continuously when you have it in reverse (unless you switch them off which is done easily enough)
* Can't get to extended height
* Dash won't indicate there is a trailer attached when you indicate

I understood LED's to be longer lasting, as well as more friendly to water which might be beneficial in your case?

Quote:

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Originally Posted by ScottD4

Hey Boggs,

The way I understand it is the LED lights on your trailer won't pulse anymore (like they did previously), however the Discovery still won't know there is a trailer attached. So:

* Rear sensors will go off continuously when you have it in reverse (unless you switch them off which is done easily enough)
* Can't get to extended height
* Dash won't indicate there is a trailer attached when you indicate

I understood LED's to be longer lasting, as well as more friendly to water which might be beneficial in your case?

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Still works - with a trailer fitted and detected it is not automatic requiring driver intervention.

Hi,
I have a MY14 d4.

I got the internal module from electronic design (sorry forgot the name).
it comes with a switch to turn it on or off.

If I forget to turn it on I find both indicator lights in my van will flash at the same time when I use the indicator. A good way to remember to turn it on as I always check the lights after connecting the van, well mostly.

I must admit I did not notice the difference otherwise in towing but that is probably me.

Without the module the car did not recognize a trailer was connected. There was no green trailer displayed in the console when you flicked the indictor.

So yes the MY14 still has the problem but I believe a bit different from other years.

Richard

Quote:

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Originally Posted by Boggs

I recall seeing a post here that said the problem was not an issue on a 14MY or later. I can't find it.
I'm ordering a new boat trailer and would consider requesting the manufacturer not put the standard LED lights on it if it is going to cause hassles. Frankly I can't see any advantage of LEDs on a trailer of any sort. I doubt power savings would be an issue as you would generally have the engine running with the lights on.

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LED lights are not recognised by the D4, you will need to fit at least one resistor or fit incandescent indicators, have just gone through this with my MY15, see top of page

hi, I'd like to do the same but wondering did you simply wired the resisters in line with each of the indicators (ie cut the cable and soldered resister in) or did they have to cross to the earth?

Across to earth. What you are describing is putting the resistor in series with the LED lights, they need to be in parallel.

Please note resistors can run very hot. Please either insulate them accordingly or mount them to metal surfaces in areas where they can dissipate heat safely.