L322 Trailer Light Electrics

Looks Good :BigThumb::BigThumb:

thank you i have had this problem with camper trailer
kent

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Originally Posted by 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: Installing a Trailer Brake Control in a Range Rover III/L322/LM 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.

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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

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.

Quote:

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Originally Posted by 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.

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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.

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.

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

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

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.

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Originally Posted by 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

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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.