L322 Trailer Light Electrics

[rm1991]

Hey all, just had a look at an L322 TD6 today and couldn't find where the trailer lights electrics/plug would be. The owner had never towed with it so he had no idea, but it is fitted with the tow option but was struggling to find where i'd plug the trailer into!

I read in another post here that it was possibly an extra option... why?! if it was an extra and wasn't fitted to this car how much would i be up for?

[RangieBit]

G'day RM,

If you can't see a big old fashioned round 7 pin plug (usually toward the passenger side) when you look at the rear of the vehicle then it's possibly a good sign that the towing pack was never fitted.

Next thing is to open the cover over the rear fuse box (drivers side rear in the cargo area). There is an additional little box in there. Refer attached pic.

If it doesn't have this box of electronic wizardy then it's about $600 to obtain and fit. This device is so that the car computers know that there is a trailer attached and don't attempt to do silly things, like alter the height of the vehicle during travel, and other more mundane things.

HTH. Cheers,
Iain

[rm1991]

Thank's RangieBit, there was no plug at the rear of the vehicle, and I don't recall seeing this little white box in with the fuse box... not that I knew what i was looking for in there anyway!

Where would you recommend getting it fitted? Presumably a dealer would be more costly than elsewhere...

[jsp]

Does your car have the tow pack electrics as pictured above? Mines got a flat 7 pin plug tucked right up under the car it took me 5 mins to work it out.

[rm1991]

We had a pretty good look under the car and around the tow bar... and nothing was obvious, so pretty sure this little (fundamental) gadget wasn't fitted!

[harlie]

The tow bar receiver is part of the car - they all have it. The tow pack option was the electrics, there was one that I looked at that had the hitch and ball, but no electrics.

The small box in Iain's pic is what to visually check for. It's the Trailer Light Module, it's a plug in device so you could check the UK's many sites, even for a 2nd hand part. You need this unit, If you try and wire up trailer lights the old fashioned way (splice into the tail light harness) the LCM (Light Control Module) will sense the extra load and turn the circuit (you car's tail lights) off thinking there is a short... As Iain said the car also makes some electronic changes once a trailer is detected.

Once you have this installed, if you want to run trailer brakes or have LEDs on your trailer there is more todo.

[33chinacars]

Hi Harlie can you explain more about wireing up tralor brakes . I have a P3 that I have not fitted yet. Thanks in advance. I'm hopeless with electrics


Gary

[harlie]

Hey Gary.

There are two issues with electric brakes that the L322 share with D3, D4 and RRS, solving them is the same process but the bits are in different spots....

1st is the harness from the Trailer Light Module to the factory 7 pin plug under the bumper is not Aus standard - its EU and the colours are different not that it is the colours that are the problem but it adds to the confusion. Big problem here is that EU has 2 tail light circuits, pin 7 and pin 5. You need pin 5 for trailer brakes so the wire going to pin 5 (brown) has to be cut and joined to the wire going to pin 7 (Black), you need to join these to prevent getting a light out message every time you connect a trailer - the TLM checks both indicators, brake and tail lights in the L322. I did this about 100mm from the TLM. If the previous owner has towed the dealer may have already done this bit, or part of it (yes the dealers are cutting and soldering the factory harness, but only when fitting a controller or if the owner complains!) - first pull the socket off the car and check it matches the EU diagram below – giveaway is black in the middle instead of brown. This first bit is really important, in the D3/4 section there was a write up by a bloke in Melb who picked up a new van and towing it home the auto lights turned on resulting in van brakes locking up (auto elec who installed the controller didn't know about this 1st issue).

While you’re there cut the wire going to pin 2 – it has the rear fog lights and it’s caused many problems on here when a trailer is used with something connected to pin 2, I connected the reverse lights so the camper has reverse lights, handy when arriving at camp in the dark.


2nd is the connection of the “Brake light sense” wire (red) for your new controller. It must connect to the output of the LCM. Usually this connects to the brake light switch under the brake peddle, but in later euro cars the switches are Hall Effect meaning that they won’t be giving a 12v signal when on. So it needs to connect to the wire carrying the brake light signal to the TLM from the LCM (not the actual brake light). "Red brake switch sense wire connected to Black/Blue wire coming out of top connector of the Light Check Module (LCM)".

Take a look at: http://www.rangerovers.net/outfitting/towing/lm/brakecontrol.html it details a LHD vehicle but the only difference is that you want the controller on the other side which makes it heaps easier, mine is recessed into the pocket where the OBD2 port is - just make sure you solder and don't use those stupid blue connectors like he has, they don't last...

The output from the brake controller (Blue wire) can then be connected to the (Brown) tail that was cut (going to pin 5) while solving the first problem. The result will be the brake controller feeding pin 5 and TLM feeding both tail light wires to pin 7.

The Aus standard is also in the attachment.

[33chinacars]

Hi Harlie

Thanks for that. Mine has a factory EU 7 pin Socket & an AU 7 pin socket bridged from the EU socket. So without checking that part may be O'k. Was there when I bought it. I have also fitted a 5 pin socket as well, bridged from the 7 pin. Like to have both 5 & 7 pin for different trailers, sometimes not mine.

Only need to sort out the brake controller. I think. May end up putting mine on top of the dash next to the A pillar. Looked at the little cubby but I not sure if unit will fit in there. What unit are you using.

Gary

[harlie]

...

What unit are you using.

Gary

P3...

[33chinacars]

Looks Good :BigThumb::BigThumb:

[kent]

thank you i have had this problem with camper trailer
kent
Hey Gary.

There are two issues with electric brakes that the L322 share with D3, D4 and RRS, solving them is the same process but the bits are in different spots....

1st is the harness from the Trailer Light Module to the factory 7 pin plug under the bumper is not Aus standard - its EU and the colours are different not that it is the colours that are the problem but it adds to the confusion. Big problem here is that EU has 2 tail light circuits, pin 7 and pin 5. You need pin 5 for trailer brakes so the wire going to pin 5 (brown) has to be cut and joined to the wire going to pin 7 (Black), you need to join these to prevent getting a light out message every time you connect a trailer - the TLM checks both indicators, brake and tail lights in the L322. I did this about 100mm from the TLM. If the previous owner has towed the dealer may have already done this bit, or part of it (yes the dealers are cutting and soldering the factory harness, but only when fitting a controller or if the owner complains!) - first pull the socket off the car and check it matches the EU diagram below – giveaway is black in the middle instead of brown. This first bit is really important, in the D3/4 section there was a write up by a bloke in Melb who picked up a new van and towing it home the auto lights turned on resulting in van brakes locking up (auto elec who installed the controller didn't know about this 1st issue).

While you’re there cut the wire going to pin 2 – it has the rear fog lights and it’s caused many problems on here when a trailer is used with something connected to pin 2, I connected the reverse lights so the camper has reverse lights, handy when arriving at camp in the dark.


2nd is the connection of the “Brake light sense” wire (red) for your new controller. It must connect to the output of the LCM. Usually this connects to the brake light switch under the brake peddle, but in later euro cars the switches are Hall Effect meaning that they won’t be giving a 12v signal when on. So it needs to connect to the wire carrying the brake light signal to the TLM from the LCM (not the actual brake light). "Red brake switch sense wire connected to Black/Blue wire coming out of top connector of the Light Check Module (LCM)".

Take a look at: Installing a Trailer Brake Control in a Range Rover III/L322/LM (http://www.rangerovers.net/outfitting/towing/lm/brakecontrol.html) it details a LHD vehicle but the only difference is that you want the controller on the other side which makes it heaps easier, mine is recessed into the pocket where the OBD2 port is - just make sure you solder and don't use those stupid blue connectors like he has, they don't last...

The output from the brake controller (Blue wire) can then be connected to the (Brown) tail that was cut (going to pin 5) while solving the first problem. The result will be the brake controller feeding pin 5 and TLM feeding both tail light wires to pin 7.

The Aus standard is also in the attachment.

[Daniel]

Hi Harlie

I have to drive up to Brisbane on Sunday and pick up a camping trailer with electric brakes.
I have just purchased a P3 controller and need to do a quick hook up.

Without going into it too far do I need to run any wires from the P3 to the back of the L322 or do I use some existing wires?

thanks in advance

[harlie]

Sorry Daniel, been away and didn't see this...

For the record.
1 New wire (blue) has to be run to the rear. You can splice into the harness at the trailer ECU, but there is nothing from the front to use.

[Daniel]

Sorry Daniel, been away and didn't see this...

For the record.
1 New wire (blue) has to be run to the rear. You can splice into the harness at the trailer ECU, but there is nothing from the front to use.

Yeah thanks - all the explanations both here and USA rangerovers.net are unnecessarily complicated.

The 2007 + L322 RR do not have the OBDII hole in the dash and there is no other suitable place to mount the P3.

I mounted the P3 on a small bracket that I made up and bolted it to the front lhs driver's seat mount bolt. I then ran a 3 core wire under the seat, under the rear carpet on through under the rear carpet to the rhs rear electrical panel.

-12v (earth) was obtained from the seat bolt and the other 3 connections ( +12v, brake lamp and trailer brake wires) spliced into the relevant wires between the trailer ECU and the trailer plug. Simple, done in a few minutes and not affecting any vehicle wiring or needing to remove any complicated interior trim panels.

In hind sight, once the P3 is initially set up there is no need to look at it or ever touch it again so a mount hidden away under the driver's seat would have done the job.

[harlie]

That's an easy way to do it, only down side is if the trailer has a short in the brake light circuit, the trailer ecu will turn the circuit off and you will have no brakes. That's why it's recommended getting the signal before the trailer ecu.

[Daniel]

yes good point, but the pre trailer ECU brake lamp wire is also there in the lhs rear wiring compartment.

[33chinacars]

Please correct me if I'm wrong But I think legally you must be able to reach unit in an emergency to operate manual override.

Gary

[Daniel]

The fella that I bought the van from had a unit mounted in his jeep that had no manual over ride.
I think that that is the beauty of the P3 - the manual lever - especially good for off-roading. Mounting under the seat would still allow access to the lever.

[harlie]

Please correct me if I'm wrong But I think legally you must be able to reach unit in an emergency to operate manual override.

Gary

No, although it is highly recommended.

The ADRs are very vague and don’t mention anything about brake control/actuation, they just talk about how many wheels (need to be braked), the need for breakaway system over 2000kg, and that override is ok under 2000kg.

QLD legislation (I live in QLD and have only checked QLD) then expands to say:-
“Except for over-run brakes, all brakes must be operable from the driver's seat of the towing vehicle.”
Still a bit vague but, “operable” is satisfied by putting your foot on the brake pedal if the brake light switch will activate the trailer brakes.

Legally, you don’t need to be able to reach the controller but it is highly recommended.

[33chinacars]

Thanks Harlie

My different interpretation of the ARD rule

Gary

[MichalNY]

Hey Iain,

Hope you are doing well. As Im doing more research I see that I seem to be following your footsteps. I also got the Traxide isolator, and looking at a Yellowtop battery. However, with 55Ah, and just half of that as usable capacity I'm wondering if that's the way to go.
What do you have hooked up to your battery, is it just your radios? Do you know if Traxide works with Lithium batteries?
Lastly, how do you have your radios mounted? Would you mind sharing some pictures? Thank you in advance

Regards,
Michal
KD2KBH



G'day RM,

If you can't see a big old fashioned round 7 pin plug (usually toward the passenger side) when you look at the rear of the vehicle then it's possibly a good sign that the towing pack was never fitted.

Next thing is to open the cover over the rear fuse box (drivers side rear in the cargo area). There is an additional little box in there. Refer attached pic.

If it doesn't have this box of electronic wizardy then it's about $600 to obtain and fit. This device is so that the car computers know that there is a trailer attached and don't attempt to do silly things, like alter the height of the vehicle during travel, and other more mundane things.

HTH. Cheers,
Iain

[drivesafe]

Hi Michal, and with the TRAXIDE DT90 isolator and an Optima D34 Yellowtop, you have over 90Ah available, and if you set the DT90 accessories Cut-Out from 11.6v to 10.5v ( which you can safely do with the Yellowtop ), you will have in access of 100Ah available.

Next, contrary to some of the misleading advertising used to sell Lithium batteries, they are NOT drop-in replacements for AGM batteries.

They can not be used in a system that has a conventional isolator, because the higher settled voltage of a lithium battery means the voltage at the isolator is actually higher than the "Turn-On" setting, so the isolator will only turn off if the lithium battery goes flat.

You must fit a DC-DC device to be able to charge the Lithium and to separate the lithium battery from the cranking battery when the motor is off.

This also means you will need at least a 100Ah to a 120Ah lithium battery to be able to have the same amount of usable accessories battery capacity, to equal what the TRAXIDE system gives you with just a 55Ah Optima.

And the disadvantages don’t end there.

With the TRAXIDE system, if you have been camping and you have discharged both batteries down to their limit, a one hour drive will have both batteries back up around 95%, but because a DC-DC device is much slower to recharge ANY battery, you will need to drive for 4 to 6 hours to replace the same amount of used battery capacity.

[Graeme]

Hello Michal,

I have a 100AH AGM in the right rear spot. It required the removal of the rear edge from the surrounding plastic panel and the wiring harness that was laid across the bottom to be lifted clear of the battery.
I have an Icom 7100 mounted on the back of the nearby rear seat with the cable to the head unit laid above the rear footwell carpet but under the rubber mat.