Tow Bar Electrics (7pin) help needed

[jpower]

Greetings - Today along with the help of my more technical buddy we installed a Westfalia detachable swan neck towbar (pfjones eBay) on my 2011 rx450h and that all seemed to have gone rather well.

Problem I am left with is getting the electrics wired up, I have the the universal bypass relay, but it seems to want me to splice into the wiring for brakes, indicators etc and I really don't want to do that.  I cannot find any instructions on the web so far either.

I wanted to know or assume that there is a plug somewhere in the rx which is used when Lexus install the towbar and if anyone had any clue about the wiring diagram so I know which is which, to be honest any help would be great.  If someone had the install done maybe they know where the electrics were plugged into.

I assume if I am carrying bikes I would need to have a light board and plates plugged in?

[Gliderpilot]

Hi

I've just had one fitted to my 450 and I was advised to get the dedicated kit and when it was fitted I can see why. Yes it cost a bit more but in all it was far easier to fit. the only wire to cut was the one to both rear fog lights as the bypass electronics cuts out the car fog lights when the trailer is fitted. I had the 13 pin unit and the lighting all went through one connector which had a jumper connector to fit between the plug and socket in the car loom. In my opinion the 13 pin connectors a far superior to the old 12N and 12S plugs. I have a paper copy of the instructions for the fitting of the bypass unit which is an all-in-one box which does the lighting bypass, split charging and sound for indicators. Worth the investment I think.

[jpower]

13 hours ago, Gliderpilot said:

Hi

I've just had one fitted to my 450 and I was advised to get the dedicated kit and when it was fitted I can see why. Yes it cost a bit more but in all it was far easier to fit. the only wire to cut was the one to both rear fog lights as the bypass electronics cuts out the car fog lights when the trailer is fitted. I had the 13 pin unit and the lighting all went through one connector which had a jumper connector to fit between the plug and socket in the car loom. In my opinion the 13 pin connectors a far superior to the old 12N and 12S plugs. I have a paper copy of the instructions for the fitting of the bypass unit which is an all-in-one box which does the lighting bypass, split charging and sound for indicators. Worth the investment I think.

Any chance you can post of a pic of the instructions?

I don't use a trailer, its strictly for carrying bikes so the 12N 7 pin I think is more then adequate for my needs, after spending so much on the towbar already I would love to avoid spending more on the dedicated kit which I have already purchased if I can help it.

[Gliderpilot]

You'll find the instructions for the dedicated kit here.

https://www.pfjones.co.uk/pfjoneswiringkits/19670502PF_Lexus_RX450h_RX350_RX270_12-16_7PIN_PF_Jones_Towbar_Electrics.pdf

it may not be of much help.

[jpower]

2 hours ago, Gliderpilot said:

You'll find the instructions for the dedicated kit here.

https://www.pfjones.co.uk/pfjoneswiringkits/19670502PF_Lexus_RX450h_RX350_RX270_12-16_7PIN_PF_Jones_Towbar_Electrics.pdf

it may not be of much help.

Your write that is not going to help, its also not for my year of car.  If that's the dedicated it still looks crazy.  I done this install on my X5 and I am sure it was plug and play into one socket.

[Gliderpilot]

16 minutes ago, jpower said:

Your write that is not going to help, its also not for my year of car.  If that's the dedicated it still looks crazy.  I done this install on my X5 and I am sure it was plug and play into one socket.

I thought that when I got my kit but the Westfalia and Lexus part numbers are the same for 09 to 15 as the kits on PF Jones website and the kit fitted with no problem. Lexus is not plug and play both the car I have now and the 400h I had previously where not equipped with a towing socket wiring already in the loom. the 400h was worse as I had to run cables from the Battery in the front to the rear and also a connection had to be made above the roof lining in the rear. It was a swine to do.

[welland]

11 hours ago, Gliderpilot said:

I thought that when I got my kit but the Westfalia and Lexus part numbers are the same for 09 to 15 as the kits on PF Jones website and the kit fitted with no problem. Lexus is not plug and play both the car I have now and the 400h I had previously where not equipped with a towing socket wiring already in the loom. the 400h was worse as I had to run cables from the battery in the front to the rear and also a connection had to be made above the roof lining in the rear. It was a swine to do.

Which wire in the roof lining of your 400x did you need to connect to?

Was the connection to the Battery to provide 12v supply to the caravan for charging leisure Battery, etc?

[Gliderpilot]

11 hours ago, welland said:

Which wire in the roof lining of your 400x did you need to connect to?

Was the connection to the battery to provide 12v supply to the caravan for charging leisure battery, etc?

I think it was for the reversing lights, as they got to the tailgate. On the 400h the Battery is in the front so I ran wires in a plastic conduit to the rear under the car. I didn't use the dedicated wiring kit but the generic one and it worked fine.

[jpower]

So is it true to say whether you get universal or the dedicated you are still splicing and even the dedicated is not just plugging into some hidden socket in the boot?

[Gliderpilot]

When my kit was fitted to the 450h, only one wire had to be found and cut to splice in the bypass for the fog lights. The electronics unit knows when the trailer or caravan is plugged in and prevents the car rear fog lights from lighting whilst towing. The rest of the wiring was plug and play, down in the bottom of the boot on the passenger side there is a muti-pin connector that is unplugged and then connected to the new towing harness. This plug and socket is behind the Sub Woofer if you have one so that will need to be removed.

 

[giggs]

Evening guys,

Installing towbar to my 2010 RX450h, all going well considering paper manual not very user friendly.

Could somebody help with wirring?

Can't figure out which wire should be connected to green/black for reverse lights??

Using Westfalia dedicated wirring kit.

Any guidance would be much appreciated.

Giggs

[welland]

On 9/17/2019 at 7:59 PM, Gliderpilot said:

Hi

I've just had one fitted to my 450 and I was advised to get the dedicated kit and when it was fitted I can see why. Yes it cost a bit more but in all it was far easier to fit. the only wire to cut was the one to both rear fog lights as the bypass electronics cuts out the car fog lights when the trailer is fitted. I had the 13 pin unit and the lighting all went through one connector which had a jumper connector to fit between the plug and socket in the car loom. In my opinion the 13 pin connectors a far superior to the old 12N and 12S plugs. I have a paper copy of the instructions for the fitting of the bypass unit which is an all-in-one box which does the lighting bypass, split charging and sound for indicators. Worth the investment I think.

I now have a facelifted 2012 rx450h for which I am looking for a tow bar and electrics module.  With the canbus plug in electrics module, I'm surprised it is necessary to cut in to the fog light cables. I wonder why the towing module does not send a msg through the ecu to the fog light module to tell it to switch off the rear fog lights?

I was wondering if my car would have a built in dashboard light to show the trailer indicators are active instead of relying on a buzzer in the towing module?

[welland]

On 2/9/2023 at 6:25 PM, giggs said:

Evening guys,

Installing towbar to my 2010 RX450h, all going well considering paper manual not very user friendly.

Could somebody help with wirring?

Can't figure out which wire should be connected to green/black for reverse lights??

Using Westfalia dedicated wirring kit.

Any guidance would be much appreciated.

Giggs

With this dedicated wiring kit from Westfalia, how do you know that the trailer indicators are flashing? Does the car make a beeping sound, or display a light on the dash?  Or is there a beeping sound emitted by the wiring kit?