LED trailers

[gavinwibrow]

I recently went through the angst of trying to fit an "adapter" to ensure my D4 would recognise and operate the LED indicator and brake lights on my caravan.

The auto elec advised me that when he tried to connect the "linear electronic design" unit, all lights would flash when the indicators were activated.
In the end we gave up, only to find that when I later connected up the van, everything worked perfectly!!!

Does this mean that I was misinformed and the D4s don't need an extra unit and read the LED scenario, or
I have a hidden as yet undiscovered control unit (most unlikely), or
wot the f is going on????

Hopefully, I now have a surplus complete set of bits and bobs to set up a D3 (or 4?) for LED trailering that I can pass on to someone needy.

I hate this electrickery stuff!

[kelvo]

D4s only need load resistors on the trailer indicator circuit to let the car know a trailer with LEDs is attached.

This will disable rear parking sensors, disable the rear fog lights, disable automatic height adjustment when a TR setting is changed (Manual height changes still work), enable a different shift program for the auto box, and flash the trailer icon on the dash when indicating.

I have wired two load resistors into the trailer socket wiring via a switch. Normal trailer lights do nothing, LED trailer lights flick switch on.

[Dagilmo]

Great timing Gavin. I've been reading heaps of threads on this one. Got to the point I know I need resistors in the system on the new car (after having the full unit in the D3) but didn't want to have to do each trailer (camper, tinny, box, and lights on the bike carrier.)

@kelvo, do you have details of what you have done? Or are they in a post I've missed somewhere?

[gavinwibrow]

D4s only need load resistors on the trailer indicator circuit to let the car know a trailer with LEDs is attached.

This will disable rear parking sensors, disable the rear fog lights, disable automatic height adjustment when a TR setting is changed (Manual height changes still work), enable a different shift program for the auto box, and flash the trailer icon on the dash when indicating.

I have wired two load resistors into the trailer socket wiring via a switch. Normal trailer lights do nothing, LED trailer lights flick switch on.

Thanks for that, now to highjack my own thread.
I have LLAMS, and my normal driving preference is to leave LR as standard, but to drop the LLAMS devilry (almost permanently) one notch. Not only does this mean slightly lower travel, but also that I can actually fit in my garage without slamming the roofrack into the garage door.
I also propose to continue this approach when towing my 3T+ brick, particularly on gravel roads.
Any problems perceived with this approach?

[kelvo]

Great timing Gavin. I've been reading heaps of threads on this one. Got to the point I know I need resistors in the system on the new car (after having the full unit in the D3) but didn't want to have to do each trailer (camper, tinny, box, and lights on the bike carrier.)

@kelvo, do you have details of what you have done? Or are they in a post I've missed somewhere?

I used these resistors 2x 25W LED 6.8Ohm Load Resistor For Hyper Turn Signal LED Controlle HOT J7C9 | eBay (https://www.ebay.com.au/itm/2x-25W-LED-6-8Ohm-Load-Resistor-For-Hyper-Turn-Signal-LED-Controlle-HOT-J7C9/192633839872?pageci=9d0647e2-0d1c-492c-b4ec-74b09570cb56) and this switch Round Rocker Switch - Red Actuator | Jaycar Electronics (https://www.jaycar.com.au/round-rocker-switch-red-actuator/p/SK0994) (Website description is wrong it is actually a DPDT switch).

I spliced into the left and right indicator tow socket wiring in the left hand boot compartment. These two cables connect to one pole each of the switch. I mounted the switch so it is tucked on the sloping underside near the 12v outlet on the left side in the boot. Then two cables from the switch to the resistors, the resistors are then connected to the body ground point. I mounted the resistors to an aluminium heatsink that I already had, then mounted the heatsink to the back of the towhitch bracket in the left side storage area. The photo shows the heatsink in place, but with the polystyrene hitch holder not fitted yet. The resistors are tucked away on the back so are physically protected.

[kelvo]

Thanks for that, now to highjack my own thread.
I have LLAMS, and my normal driving preference is to leave LR as standard, but to drop the LLAMS devilry (almost permanently) one notch. Not only does this mean slightly lower travel, but also that I can actually fit in my garage without slamming the roofrack into the garage door.
I also propose to continue this approach when towing my 3T+ brick, particularly on gravel roads.
Any problems perceived with this approach?
If you are permanently driving with a lower than standard ride height I would be getting a wheel alignment done at that height.

[dirvine]

I have read widely and in reality you only need one resistor, not 2. Prior to fitting a resistor, my caravan LEDS all worked OK and the flash was consistent and not any different to a trailer attached or not. I have mine fitted to the RH circuit only. After I did that I suddenly noticed the change in driving characteristics of the car. My actual fuel usage reduced, gear changes seemed to be a touch higher in the rev range and the car seemed to have more power when driving.

[kelvo]

I have read widely and in reality you only need one resistor, not 2. Prior to fitting a resistor, my caravan LEDS all worked OK and the flash was consistent and not any different to a trailer attached or not. I have mine fitted to the RH circuit only. After I did that I suddenly noticed the change in driving characteristics of the car. My actual fuel usage reduced, gear changes seemed to be a touch higher in the rev range and the car seemed to have more power when driving.

This is correct for the car to ‘sense’ that a trailer with LEDs is attached.

I fitted two (One on each indicator) to satisfy my OCD for dash trailer icon to flash when either indicator is used. With only one resistor fitted the dash trailer icon will only flash when indicating with the side that has the resistor fitted.

Plus when it only costs $4.45 for a pair of resistors why not fit both?

[gavinwibrow]

This will disable rear parking sensors, disable the rear fog lights, disable automatic height adjustment when a TR setting is changed (Manual height changes still work), enable a different shift program for the auto box, and flash the trailer icon on the dash when indicating.

Thanks Kelvo. You have given me food for thought.
Having just had my first tow experience pulling the brick, I was almost convinced I already unknowingly have the resistors fitted, cos the exercise was so effortless compared to using my D2.
However, I don't get the green towing sign, and I haven't yet checked reverse to see if the reversing sensors are turned off, rear fogs disabled etc, so a work in progress for my next tow.

[Eric SDV6SE]

If you haven't got the green triangle symbol showing up on the dash each time you indicate, the car does not know it is towing and none of the features as mentioned by Kelvo are active.

[gavinwibrow]

If you haven't got the green triangle symbol showing up on the dash each time you indicate, the car does not know it is towing and none of the features as mentioned by Kelvo are active.

Cheers Eric.
That certainly is my first and logical assumption, but before I go ahead with the resistors I want to revisit the wiring because on both sides there are additions which might be masking any fitment of resistors. I have a CB radio unit in the left along with part of the jack and some spares, and the Traxide control box and a couple of extra Anderson and fridge wires on the right. For someone like me, it does my head in, so another trip to the auto elec is on the cards. [bawl]

[Eric SDV6SE]

I fitted the load resistors to the camper tail light wiring loom instead of to the car, as I don't own a trailer. Saves splicing into the cars wiring. Next step is a rig between the car plug and the camper plug, these should be relatively easy to make by a good auto sparky: the load resistors are cheap and they just splice into the adapter wiring harness, like a Narva round to flat pin adapter.

[dirvine]

This is correct for the car to ‘sense’ that a trailer with LEDs is attached.

I fitted two (One on each indicator) to satisfy my OCD for dash trailer icon to flash when either indicator is used. With only one resistor fitted the dash trailer icon will only flash when indicating with the side that has the resistor fitted.

Plus when it only costs $4.45 for a pair of resistors why not fit both?
I bought the Navara one. Wish it was only $4.45!. The other reason I only fitted one is that I fitted a "conversion" adapter... Round plug to a flat 12 pin plug and so just added the resister to the adapter. It only "warms up when I turn on the indicator so I mounted it on a small piece of metal to act as a heat sink of sorts. After all I have a bit of scottish blood in me and I am "canny" with my money!!!!

[Dagilmo]

I used these resistors 2x 25W LED 6.8Ohm Load Resistor For Hyper Turn Signal LED Controlle HOT J7C9 | eBay (https://www.ebay.com.au/itm/2x-25W-LED-6-8Ohm-Load-Resistor-For-Hyper-Turn-Signal-LED-Controlle-HOT-J7C9/192633839872?pageci=9d0647e2-0d1c-492c-b4ec-74b09570cb56) and this switch Round Rocker Switch - Red Actuator | Jaycar Electronics (https://www.jaycar.com.au/round-rocker-switch-red-actuator/p/SK0994) (Website description is wrong it is actually a DPDT switch).

I spliced into the left and right indicator tow socket wiring in the left hand boot compartment. These two cables connect to one pole each of the switch. I mounted the switch so it is tucked on the sloping underside near the 12v outlet on the left side in the boot. Then two cables from the switch to the resistors, the resistors are then connected to the body ground point. I mounted the resistors to an aluminium heatsink that I already had, then mounted the heatsink to the back of the towhitch bracket in the left side storage area. The photo shows the heatsink in place, but with the polystyrene hitch holder not fitted yet. The resistors are tucked away on the back so are physically protected.

Hi kelvo,

Thanks for the effort to post the details. Onto the job list it goes.

Cheers David.

[Redback]

I turn my headlights on when I have our trailer on with LEDs, everything works fine after that, actually I drive with the headlights on all the time anyway.

Only thing that doesn't work is the trailer symbol on the dash when you use your indicators, no big deal, I have LLAMS, UHF and HF radios, fridges, extra sockets and many other devices in our D4, no need to worry about parking sensors as we turned them off, everything works fine.

There's heaps of info on the forum about what people have done with the D4 regarding LEDs, as said by someone above the D4 doesn't need a device like the D3 needs, just a resistor and if the auto elec actually knew what he was doing he should be able to make something very simple up for you.

Might wanna try using a LR independent specialist, they should know what to do, I know our local indi LR guy does.

[superhet]

After buying a Jayco van with LED lights I learnt that most European cars test the bulbs to alert you of a blown bulb. This is the cause of the fast flashing LEDS.

After looking around for a solution I found there were some very expensive solutions being sold online. Being a bit of a Scrooge I thought ‘how had can this be?’ I just need to make the car think there are bulbs on the trailer. So I put resistors across the circuits going to the van tail light, stop light, left and right blinker. For the stop and blinkers an 8ohm 25W resistor and for the tail light 16ohm. I mounted all these in a diecast box on the A frame and piggybacked the wiring to the plug. Maybe this is a bit of overkill but it works and didn’t cost much.

[Eric Mac]

Hello all, I recently joined the ranks of D4 owners. And I am still coming to terms with all the electrickery after 20 years driving a 96 110.

I have the issue of the D4 not recognizing the camper trailer with LED lights. I have read another thread suggesting fitting the Ford Ranger adapter (AB3915436BF LED Trailer jumper connector) as it has in built resistors. Well I bought one and it hasn't made a difference.

I still have park sensors active and no trailer signal on the dash. Any advice would be helpful.

Thanks Eric

[Dagilmo]

I used these resistors 2x 25W LED 6.8Ohm Load Resistor For Hyper Turn Signal LED Controlle HOT J7C9 | eBay (https://www.ebay.com.au/itm/2x-25W-LED-6-8Ohm-Load-Resistor-For-Hyper-Turn-Signal-LED-Controlle-HOT-J7C9/192633839872?pageci=9d0647e2-0d1c-492c-b4ec-74b09570cb56) and this switch Round Rocker Switch - Red Actuator | Jaycar Electronics (https://www.jaycar.com.au/round-rocker-switch-red-actuator/p/SK0994) (Website description is wrong it is actually a DPDT switch).

I spliced into the left and right indicator tow socket wiring in the left hand boot compartment. These two cables connect to one pole each of the switch. I mounted the switch so it is tucked on the sloping underside near the 12v outlet on the left side in the boot. Then two cables from the switch to the resistors, the resistors are then connected to the body ground point. I mounted the resistors to an aluminium heatsink that I already had, then mounted the heatsink to the back of the towhitch bracket in the left side storage area. The photo shows the heatsink in place, but with the polystyrene hitch holder not fitted yet. The resistors are tucked away on the back so are physically protected.

Hey Kelvo (and others),

Just bought the gear to do the job. Is the attached a correct wiring diagram of your description?

152714

[kelvo]

Hey Kelvo (and others),

Just bought the gear to do the job. Is the attached a correct wiring diagram of your description?

152714
Yes, that’s how I did mine [thumbsupbig]

[Dagilmo]

Yes, that’s how I did mine [thumbsupbig]

Great. Thanks for the reply. Jobs on!

[CraigE]

Hi Kelvo,
Will be doing this to mine soon. What is the purpose of the switch? I would have thought if you splice in the resistors that would be all that would be needed and should be fine for either led or conventional light trailers?
Had to do similar with the Defender when running LEDS but no switch.
Cheers
Craig

Yes, that’s how I did mine [thumbsupbig]

[kelvo]

Hi Kelvo,
Will be doing this to mine soon. What is the purpose of the switch? I would have thought if you splice in the resistors that would be all that would be needed and should be fine for either led or conventional light trailers?
Had to do similar with the Defender when running LEDS but no switch.
Cheers
Craig

Because without the switch the resistors will be in circuit all the time making the D4 think there is always a trailer attached.

[101RRS]

My led box just plugs into the trailer socket in the car and the trailer wiring plugs into the LED box - so the box is only connected when using the trailer.

Garry

[Ferret]

Where I installed mine.

[CraigE]

Because without the switch the resistors will be in circuit all the time making the D4 think there is always a trailer attached.
Interesting. I know I had to do the same with the Defender TD5 but didnt require the switch and it all worked as it should, but that does not have all the electrics the D4 has either.
Was hoping there was a permanent simple fix.
Thanks for the reply I know have one of three options.
Cheers
Craig

[Tombie]

Interesting. I know I had to do the same with the Defender TD5 but didnt require the switch and it all worked as it should, but that does not have all the electrics the D4 has either.
Was hoping there was a permanent simple fix.
Thanks for the reply I know have one of three options.
Cheers
Craig

There’s a 4th option, a clever unit that senses when it’s needed.

It’s also about $480.00

[CraigE]

There’s a 4th option, a clever unit that senses when it’s needed.

It’s also about $480.00
OUch. For a car that should have been set up to cope with this from factory.

[Tombie]

OUch. For a car that should have been set up to cope with this from factory.

It’s almost not possible. Too many variables with LED.

[CraigE]

It’s almost not possible. Too many variables with LED.
I think I might just put resistors on the trailer, much easier.

[Eric SDV6SE]

I think I might just put resistors on the trailer, much easier.

Exactly

[rocket rod]

I think I might just put resistors on the trailer, much easier.

The only issue with resistors on the trailer is you have limited yourself to that trailer. Borrow or hire someone else's unit and you're back to square 1. But it's the easiest to do.

[INter674]

OUch. For a car that should have been set up to cope with this from factory.

There are worse ones out there. .just ask canopy makers who fit leds to new Nissans Yotas etc and discover the dilemmas they face in resolving canbus and similar ecu based wiring issues. My future sil's shop spent a day with a sparky resolving led light issues on one truck alone. Car would not even start until the new canopy leds were sorted to the vehicles system. Other trucks he said when leds are installed cause all lights go off like party lights.

At a horse show we told a Nissan owner his side lights were on. Can't turn them off he said unless we disconnect the horse float.

So the Disco is generally more tolerant of leds at least.

[CraigE]

The only issue with resistors on the trailer is you have limited yourself to that trailer. Borrow or hire someone else's unit and you're back to square 1. But it's the easiest to do.
Yep,
why I have not totally made up my mind yet. But not keen on having a switch either that can get left on or knocked.
The Defender was much easier. LOL.
Cheers
CRaig

[Tombie]

Yep,
why I have not totally made up my mind yet. But not keen on having a switch either that can get left on or knocked.
The Defender was much easier. LOL.
Cheers
CRaig

If you place it correctly it can’t get knocked on.

If you leave it on the vehicle will show you on the dash!!!

[scarry]

Yep,
why I have not totally made up my mind yet. But not keen on having a switch either that can get left on or knocked.
The Defender was much easier. LOL.
Cheers
CRaig

The switch for mine is behind the removable panel on left of cargo area,well out of the way and easily accessible.

Much better to do the vehicle,and its very easy, so whatever you tow will be fine.

[101RRS]

Just remember if you do not have a module to use with LED lights it doesn't really matter in most cases - yes the trailer indicator lights will flicker but it is really quite dull and probably not a roadworthy issue as the indicators do still fully work at full brilliance, it is just that there is a dull flicker as the car tests for the trailer.

As far as the car is concerned - yes the parking sensor noise can be annoying but just turn them off. Other functions in the car will be turned off but really if you know this it is not such an issue.

Garry

[kelvo]

Just remember if you do not have a module to use with LED lights it doesn't really matter in most cases - yes the trailer indicator lights will flicker but it is really quite dull and probably not a roadworthy issue as the indicators do still fully work at full brilliance, it is just that there is a dull flicker as the car tests for the trailer.

As far as the car is concerned - yes the parking sensor noise can be annoying but just turn them off. Other functions in the car will be turned off but really if you know this it is not such an issue.

Garry

The LED flicker does not happen with a D4. This is why you only require cheap simple resistors to let the D4 know a trailer is attached.

[Grappler]

The simlest solution is an in line device. You can use it in different vehicles and use when you have a led trailer
This is a pic of one I made for my RRS It does have relays to defeat pulsing but you can leave them and just use the resistorsout if pulsing is not an issue
https://www.aulro.com/afvb/attachments/the-d3-d4-sticky-zone/72466d1391759499-discovery-3-led-trailer-lights-p8300520.jpg

Here is a link to the circuit

[Dagilmo]

I just did mine based on Kelvo's instructions earlier in the thread (thanks again). I made a rookie mistake by not getting a dual pole switch. All looked good with the trailer light on the dash working, until I tested the trailer and both indicators flashing. What an idiot! Funnily, while I was wiring it up I was wondering why you needed two resistors to have the dash light working on both indicators. Anyway, new switch, rewired and working perfectly. Probably $30 (including two switches [bigwhistle]).

I put the switch in the recessed panel in front of the removable panel. Easy to fit and protected by the recess and a newly installed drawer.

I put mine on the car as I have 3 trailers.

[imaz]

This is correct for the car to ‘sense’ that a trailer with LEDs is attached.

I fitted two (One on each indicator) to satisfy my OCD for dash trailer icon to flash when either indicator is used. With only one resistor fitted the dash trailer icon will only flash when indicating with the side that has the resistor fitted.

Plus when it only costs $4.45 for a pair of resistors why not fit both?

Why must the load resisters be on the indicators and not all lights such has stop, tail/parking lights?

[imaz]

I think I might just put resistors on the trailer, much easier.

Just add the resisters into the trailer plug at the drawer bar side/within the plug itself.

[Ferret]

Why must the load resisters be on the indicators and not all lights such has stop, tail/parking lights?

Because it's the indicator circuits which are probed for resistance indicating the presence of a trailer or not.

[kelvo]

Why must the load resisters be on the indicators and not all lights such has stop, tail/parking lights?
Different vehicles need different things. The D3 (Also requires relays), D4 & I would assume RRS only check the indicator circuits, so no point in adding resistors to anything else.

If, for example, you had a BMW X6 you would need resistors and relays on both indicators, tail light and brake light circuits.

[Ferret]

Just add the resisters into the trailer plug at the drawer bar side/within the plug itself.

You reckon you will be able to wire them within a standard trailer plug?

Each load resistors is about 5cm long x 1.2cm square and lets not talk about the possible need to mount them on a heat sink because they will heat if you activate and leave your hazard lights on with a trailer attached.

[Eevo]

hmm, so my local auto mech added something to my RRS instead of the trailer. should I get this changed over?

[imaz]

You reckon you will be able to wire them within a standard trailer plug?

Each load resistors is about 5cm long x 1.2cm square and lets not talk about the possible need to mount them on a heat sink because they will heat if you activate and leave your hazard lights on with a trailer attached.

This video used small resisters? But obviously she added more than we would need into the 7 flat.

LED trailer plug resistor wiring - YouTube (https://youtu.be/dUPNfc6_1ks)

[imaz]

By the way, is there a minimum wattage resister which is sufficient to trick the D4? 25w would be hot to run if you can get by with a 10w resister instead? Might be simpler to add a incandescent turn indicators on the trailer(additional lights).

[Tombie]

hmm, so my local auto mech added something to my RRS instead of the trailer. should I get this changed over?

Is it switchable? Or is the trailer symbol constantly on?

[Tombie]

By the way, is there a minimum wattage resister which is sufficient to trick the D4? 25w would be hot to run if you can get by with a 10w resister instead? Might be simpler to add a incandescent turn indicators on the trailer(additional lights).

It’s resistance that matters… ohms.
The watt rating is how much it can handle.
I use 50w normally.

[kelvo]

This video used small resisters? But obviously she added more than we would need into the 7 flat.

LED trailer plug resistor wiring - YouTube (https://youtu.be/dUPNfc6_1ks)

She used 120 ohm resistors, which is about the equivalent of a 1.6 watt load at 14.5V. I’m not convinced that will work at all with a D4, and if it does probably won’t last long as they are only rated to 1 watt. But for $0.68 you won’t have lost much if it doesn’t work 120 Ohm 1 Watt Carbon Film Resistors - Pack of 2 | Jaycar Electronics (https://www.jaycar.com.au/120-ohm-1-watt-carbon-film-resistors-pack-of-2/p/RR2552)

[imaz]

It’s resistance that matters… ohms.
The watt rating is how much it can handle.
I use 50w normally.

What are you recommending? How many ohms? Would adding just at the ground work all signals?

[Eevo]

Is it switchable? Or is the trailer symbol constantly on?

not switchable that i know of, and trailer symbol has never come on.

[Ferret]

not switchable that i know of, and trailer symbol has never come on.
Maybe you need to ask the bloke who fitted it all why you don't get the trailer symbol when you hitch a trailer.

Think you will find a hidden switch somewhere.

[kelvo]

What are you recommending? How many ohms? Would adding just at the ground work all signals?
See post #5 on the 1st page of this thread, all the info you need is there. https://www.aulro.com/afvb/l319-discovery-3-and-4-a/272077-led-trailers.html#post2916698

[imaz]

See post #5 on the 1st page of this thread, all the info you need is there. https://www.aulro.com/afvb/l319-discovery-3-and-4-a/272077-led-trailers.html#post2916698

Thanks, just picked up the below from altronics.

Plan to make an adapter for 7 Large to 7 small, with this in between. 15Ohm, 10w ceramic.
https://uploads.tapatalk-cdn.com/20210217/f6227063485f1cef36cc3584f0a610ba.jpg

[ramblingboy42]

I said to myself , "self.....when your trailer lights blow or burn out then is the time to put flash dancing leds onto the trailer"

so, 10 or 15yrs later , after replacing the rusted **** steel bottom of the trailer with formply , and replacing the **** tyres with almost **** ones , the lights are still perfect

[Tombie]

Thanks, just picked up the below from altronics.

Plan to make an adapter for 7 Large to 7 small, with this in between. 15Ohm, 10w ceramic.
https://uploads.tapatalk-cdn.com/20210217/f6227063485f1cef36cc3584f0a610ba.jpg

Take them back...

6 Ohm is what you need...
10X 50W 6ohm 6Ω Load Resistors For Hyper Flash Turn Signal Blinker LED Bulb | eBay (https://www.ebay.com.au/itm/133564867392)

[imaz]

Take them back...

6 Ohm is what you need...
10X 50W 6ohm 6Ω Load Resistors For Hyper Flash Turn Signal Blinker LED Bulb | eBay (https://www.ebay.com.au/itm/133564867392)

Wouldn’t a higher resistance just run it at less amps, cooler. altronics did have a 6ohms, 10w.

[kenl]

Wouldn’t a higher resistance just run it at less amps, cooler. altronics did have a 6ohms, 10w.

I think you will find that the low current draw from the LED lights is the the reason why the car can't detect them in the first place.

[DiscoJeffster]

The Narva ones are 8 ohm and work fine. I fitted them to my camper.

Narva Load Resistor 21W 12V 90034BL | Sparesbox (https://www.sparesbox.com.au/part/narva-load-resistor-21w-12v-90034bl)

[imaz]

The Narva ones are 8 ohm and work fine. I fitted them to my camper.

Narva Load Resistor 21W 12V 90034BL | Sparesbox (https://www.sparesbox.com.au/part/narva-load-resistor-21w-12v-90034bl)

Picked some up from superdooper cheap, $15.

Slowly setting up the box.

https://uploads.tapatalk-cdn.com/20210218/6284e682f666b2cbbf415907ddc6c669.jpg

[iannicki]

This video used small resisters? But obviously she added more than we would need into the 7 flat.

LED trailer plug resistor wiring - YouTube (https://youtu.be/dUPNfc6_1ks)

Putting aside the watts/ohm of the resistors, why splice and solder into the white/ground wire and not just attach at the screw terminal as she has done at the other end of each resistor?

I am thinking of adding a 50w/6ohm resistor into a 7-pin flat to 7-pin round adapter and cannot think why it would not be simpler to just attach the resistor via the screw terminals.

[imaz]

Putting aside the watts/ohm of the resistors, why splice and solder into the white/ground wire and not just attach at the screw terminal as she has done at the other end of each resistor?

I am thinking of adding a 50w/6ohm resistor into a 7-pin flat to 7-pin round adapter and cannot think why it would not be simpler to just attach the resistor via the screw terminals.

Because the resisters are relatively large and they do get very hot. Even the way I have done it below, I’m sceptical if it’s safe for the surrounding wires. Although it works, and it’s only the indicator circuit that the resisters heat up - I may end up just putting resistors to my camper trailer tail lights, mounting the resisters externally. Just not sure if the resisters in use are water resistant??

https://uploads.tapatalk-cdn.com/20210219/b86d1b6c2f1836be5a2165c6d0ca5cdb.jpg

[Tombie]

That’s why when I build mine I use thermal adhesive to mount the resistors to the case and turn it into a heat sink.

The higher the power handling of the resistor the better they tend to dissipate the heat generated.
I’m confident mine will be fine, if I get too concerned I’d look at potting them in thermal epoxy.

My in-line version like you’ve built was used for the last 10 years without a problem using the resistors I linked above.

The internal install version only differs in how it’s wired to the vehicle in my application.

[imaz]

That’s why when I build mine I use thermal adhesive to mount the resistors to the case and turn it into a heat sink.

The higher the power handling of the resistor the better they tend to dissipate the heat generated.
I’m confident mine will be fine, if I get too concerned I’d look at potting them in thermal epoxy.

My in-line version like you’ve built was used for the last 10 years without a problem using the resistors I linked above.

The internal install version only differs in how it’s wired to the vehicle in my application.

So despite the indicator is not always on, is the indicator circuit constantly probed, even though the trailer symbol is not continuously lit?

[Ferret]

...is the indicator circuit constantly probed, even though the trailer symbol is not continuously lit?

On a D3 they are constantly probed, which is why LED trailer lights flicker when hitched to a D3 unless other precautions are taken.

However, the D4 is different, they are only probed once, whenever specific events occur - the opening or closing doors (possibly some other events as well, I'm unsure).

So for a D4 heating of the resistors is not much of an issue during the normal course of indicator use - ie on for a few seconds to indicate a turn and then cancelled. The heat issue will most commonly arise when you leave your indicators running continuously, typically when the hazard lights are turned on.

[gavinwibrow]

And a further silly query regarding resistors etc! At least the answer/s should be simple[bigwhistle]

Am I right in assuming the heat sink is only required when the indicators are activated either by turn signal or hazard lights (D4 MY16)?

Also, having followed Kelvo's advice/suggested items, are the 25W 6.8 Ohm resistors the best sizes for fitment?
Like others, I plan to fit the pair in the LHS rear wiring hideaway where some of the tow equipment usually resides.

[Tombie]

And a further silly query regarding resistors etc! At least the answer/s should be simple[bigwhistle]

Am I right in assuming the heat sink is only required when the indicators are activated either by turn signal or hazard lights (D4 MY16)?

Also, having followed Kelvo's advice/suggested items, are the 25W 6.8 Ohm resistors the best sizes for fitment?
Like others, I plan to fit the pair in the LHS rear wiring hideaway where some of the tow equipment usually resides.

Yes and yes

Heat only generated when indicators are flashing.
25w 6.8 Ohm are perfect.

[imaz]

Deleted. Will post under brake controller topic