T27 Towbar Wiring

[graham27]

Hi all,

I've done most of the towbar wiring (oem kit) but am stuck on connecting the last wire, but am wary of breaking something if I'm mistaken - it's picture number 28 in the series of pictionary games toyota use instead of words in their manual: http://www.toyota-tech.eu/aimuploads/33a63f92-4487-4a5b-ad09-543b21d819cf/AVENSIS_WGN_THWH%207pole_PZ417-T556B-00%20_AIM_002_180-2.pdf

I think it's telling me to pull a lead "SB" out of an existing plug and replace it with the one "GR" on the end of the towbar loom. With some special tiny little pointy tool.

Presumably GR and SB are colours (grey, and goodness know what).

Can anyone assure me this is right? or shout before I break something!

thanks,

g.

ps - pretty unimpressed with the wiring - having to run a live all the way to a Battery, not the fuse box? and locate the inline fuse by cable-tying it to the Battery fixing. Feels like a right bodge.

[rogersp]

Hi

Just about to go through this exercise, did you:

receive any response to your query?

was it all straight forward

use a genuine Toyota or pattern wiring kit?

Thanks

[theoilburner]

I just fitted a tow bar with 13 pin electrics to my T27 last week. You have to cut the fog light wire near to the multi-plug and this re-routes the signal into the trailer module so that the trailer fog light works when connected but the one on the car turns off - so you don't get reflected glare.

I guess you've sorted it by now, but if not - cut the green wire and add a connector as shown in the diagram so it can be plugged into the wiring loom for the tow bar.

On a side note, I was quite disappointed at the lack of proper integration for the tow bar electrics on this car - most modern cars now just plug straight into the CANBUS and you're pretty much done. Then the parking sensors turn off, the fog light behaves, the car will tell you if a trailer bulb fails and you often get trailer stability programme too. Toyota just don't seem to have caught up here. All this snipping of wires and running power leads to the Battery belongs in the ark.

On the plus side, I didn't have to drill any holes or make cuts to the bumper - which is nice.

[rogersp]

Thank you for the response, really appreciated.

Completed the wiring yesterday with the exception of the fog light signal cable as I could not push out the connector from the plug, it appears you need a special tool. I was going to make one from a Jeweler's screwdriver, or try anyway but ran out of time.

Regarding cutting the cable, SB - Sky Blue in my case, according to the Toyota Instructions and not green, I was a bit unsure incase it was part of the Canbus system?

I presume that in cutting the cable you just made two soldered connections and insulated them with heat shrink tubing?

I've use the trailer without the fog light facility yesterday and all was OK.

I totally agree with you regarding the kit, bit of a joke having to run 12v supply from the front of the car. A simple plug in system would be much easier.

That said I'm impressed with the build quality and I base that on my last three premium German brands!

Thanks again

[theoilburner]

Just checked my instructions (mine was a Right Connections kit, not the official Toyota one) and you're right - it's a light blue wire for the fog light.

My kit didn't do anything fancy - it was a simple and literal cut of that wire, then I crimped some new connectors on the ends and slipped them into a plastic connector block that came with the kit. Not as trusty as soldering and heat shrinking true, but seems okay.

I'm with you on the build quality - despite the idiosyncrasies of Toyota design, I can't fault how they screw a car together. I was impressed when I was taking interior panels apart a) how easily and logically they came off without undue force and b) how neatly they all went back in again and fitted as good as new. Clearly it's been designed to be assembled quickly but properly. Fair play to Toyota for that.

BTW, I wouldn't recommend the Right Connections kit to anyone, they provided two diagrams for the wiring blocks (pre and post facellift) and neither matched my car. Cue lots of scratching of head to work out what the correct wires should be from which multi-connector before cutting them! Plus, they routed the wires via the bulkhead in the driver's footwell, which is a nightmare to get through the engine bay without touching hot things or moving things. Looking at the instructions for the Toyota kit, they go through an access point behind the glovebox - much nearer to the Battery and on the correct side of the car...

[graham27]

A very late reply, for completeness sake :)

I used the Toyota wiring kit, and it fitted fine.
Regarding extracting a pin from the multipin plug, I used a needle. I recall I had to slide it down under the piece of metal latching the pin in. Oh, and unclip the plastic strap thing that goes over the sides of the pins first. Very fiddly: my Saab back in 2003 was a much better thought out and simple plugin job.
Soldering & heatshrink is probably a better idea.

The towbar itself I went with Witter detachable - far more realistically priced, and so far pretty good.

[GPB4]

I have a 65 reg avensis estate, how would I get the Toyota installation instructions for this age of car please?

[Devon Aygo]

https://www.toyota-tech.eu/Aim/Aim2.aspx?pubtype=AIM&menuitem=2

[Samuel101]

Hi all.

As you might have noticed on another post, I ran into the same issues, mounting the towbar wiring kit.

It's now mounted with the grey wire from the kit going into the cars multiplug and the light blue from the cars multiplug connected to the red/yellow from the kit.

But now It seems like i can’t get the rear fog light to work ( that is without trailer off course)

Actually I don’t get the logic on this "rear fogligt cancelling system" as i think it is possible on my car at least, to have only the front fog lights on and switch the rear one on and off independently??

So am I right in assuming that in my case I don’t have to connect these “rear foglight canceling when trailing a trailer"  wires at all????

Or will there be any issues in not doing that??

I hope to sort this as I think the missing rear foglight will be a problem when going to MOT.

Any guidance and help will be very much appreciated and thanks in advance.

best regards Per

PS. What is the small Buzzer on the towbar wiring unit used for???

[2009joe]

On 6/2/2019 at 12:23 AM, GPB4 said:

I have a 65 reg avensis estate, how would I get the Toyota installation instructions for this age of car please?

hello sorry to bother you i have looked at the diagram posted below yours and well on my 2014 2.0d4d  toyota avensis t27 saloon i cant find a axcess gromit to run a wire through to the Battery. i have one big thick main bunch of wires going threw but i am afraid of dammaging them would like to get on where there less wires going threw. where did you get the cable threw the firewall buddy .really love your info as on my 2014 toyota avensis its tight and i cant see any other axcess plugs even from the inside 

[avensisnz]

I've attached the installation guide for the genuine Toyota Avensis towbar kit. On page 21 it shows a factory wiring harness that you simply plug into. Is that not the case?

My Avensis came with an after market towbar that was installed by the previous owner. Unfortunately the installer simply threw out the plastic undertray for the rear of the car instead of cutting out the required notches for the towbar. My towbar also has a really long tongue which sticks out about twice as far as a regular towbar. I have no idea why you'd need such a long tongue and it's actually less safe, because it reduces the amount of vertical load the towbar can support (due to increased leverage) and also makes towing less stable, because the tow ball is further away from the rear axle of the car. I've thought about getting the towbar removed, as I never use it, but it looks a bit labour intensive, as you have to remove the bumper and the rear muffler.

769081513_PZ408-T9563-00Avensis_Sedan_Towinghitchfixed_PZ408-T9563-00_AIM_001_266_5.pdf

[2009joe]

On 8/5/2014 at 10:27 PM, graham27 said:

Hi all,

I've done most of the towbar wiring (oem kit) but am stuck on connecting the last wire, but am wary of breaking something if I'm mistaken - it's picture number 28 in the series of pictionary games toyota use instead of words in their manual: http://www.toyota-tech.eu/aimuploads/33a63f92-4487-4a5b-ad09-543b21d819cf/AVENSIS_WGN_THWH%207pole_PZ417-T556B-00%20_AIM_002_180-2.pdf

I think it's telling me to pull a lead "SB" out of an existing plug and replace it with the one "GR" on the end of the towbar loom. With some special tiny little pointy tool.

Presumably GR and SB are colours (grey, and goodness know what).

Can anyone assure me this is right? or shout before I break something!

thanks,

g.

ps - pretty unimpressed with the wiring - having to run a live all the way to a battery, not the fuse box? and locate the inline fuse by cable-tying it to the battery fixing. Feels like a right bodge.

here is the plan for the t27 towbar  

https://www.pfjonesebay.co.uk/instructions/TO148DHU.pdf

[2009joe]

On 8/5/2014 at 10:27 PM, graham27 said:

Hi all,

I've done most of the towbar wiring (oem kit) but am stuck on connecting the last wire, but am wary of breaking something if I'm mistaken - it's picture number 28 in the series of pictionary games toyota use instead of words in their manual: http://www.toyota-tech.eu/aimuploads/33a63f92-4487-4a5b-ad09-543b21d819cf/AVENSIS_WGN_THWH%207pole_PZ417-T556B-00%20_AIM_002_180-2.pdf

I think it's telling me to pull a lead "SB" out of an existing plug and replace it with the one "GR" on the end of the towbar loom. With some special tiny little pointy tool.

Presumably GR and SB are colours (grey, and goodness know what).

Can anyone assure me this is right? or shout before I break something!

thanks,

g.

ps - pretty unimpressed with the wiring - having to run a live all the way to a battery, not the fuse box? and locate the inline fuse by cable-tying it to the battery fixing. Feels like a right bodge.

quick question  i have a rhd toyota avensis 2014 and well i want to pull a wire threw the fire wall but on my car i can only find on rubber grommet with main wires going into threw the fire wall to the fuse box. problem is this wires are right and thick wiring loom and i dont want to run my 12v 8awg  grade wire threw. i cant seem to find any more grommets to pull wires threw i only have one at the rear of my fuse box . did you fing any others on the toyota t27 

[RichardGNX]

General T27 Wireloom fitting 2015 model, 

link to harness supplied by Toyota

 

I used an aftermarket relay/ buzzer for Left, Right, Taillight and brake lights only. Soldered the to the campus wires and used general insulating tape. Panels fit nicely.
 

Long lead and fuse to Battery is a pain.