Tow bar harness electrical issue

[Cessa]

Thanks all. I believe the wiring loom is located not in the car behind the panel but possibly way up high between the bumper and the inner shell of the car. I traced where the wiring had gone from the plug and found the blue wire exposed wrapping around a bunch of wires from the plug. Without taking the bumper off, it would be impossible to utilize or even check this. So i ran the blue and red wires from the electric brake unit direct to the plug to avoid any extra work.
Bleetnblurt - all the wiring is correct and going to the right corresponding wire. Thanks.
Lowranger - i might do what you said, take the car back and get the tech to re-check his work as from what i can gather, there is something gone wrong with the original setup.

Shouldnt be the van wiring as everything was working fine when hooked up to the disco. But it is a Jayco and my confidence in their workmanship is extremely low but that is an issue for another forum.

I should mention that the overide button on the redarc did operate the vans brakes (blue wire), even though there was no red wire input. So this tells me the redarc unit does operate and the blue wire connection works fine.

[low ranger]

Cessa, I fit these for a job...the wiring loom is where I said it is. You have hooked up the blue wire into the plug as I do, but it is wise to either snip the blue wire upstream of the connection or find the live end & insulate. that is probably not causing the issue, but you don't want un-insulated live wires anywhere. The fact that the manual over ride is working tells me there is a connection problem in the brake light circuit. I fitted a brake controller on Friday to a new Hilux that did the same thing. The Toyota dealer techs had not performed the plug & play game behind the P/S tail light. It happens...

[Cessa]

Thanks low ranger and i really appreciate your advice here especially from someone who does this work for a living and seen many issues. I like to do what i can myself but sometimes taking it back to the dealer and get them to fix up what they should have done is a better fix but im ready for an argument if they should charge me for the time.

Appreciate everyones feedback and advice though. The more information, the better the decision can be made.

[low ranger]

Thanks mate. Taking it back to the dealer is not admitting defeat if the problem lies with their work/parts & your confident you have done your part right. I'd move the red trigger wire back to the trailer plug area too. In fact, from a warranty point of view, it's essential. The owner of the Hilux I was talking about asked me not to rectify Toyota's poor work as he wanted to rip it up them himself.

[Cessa]

Time for an update. Told the dealer the full story, but they don't have an auto sparky on their books so they steered me to a company they hire to perform diagnostics of this nature.
They came out and confirmed the fault but couldn't fix it as the bumpa bar had to be removed as this is where the connections were.
Drove the car to Jeep and they removed the bumpa bar and found a bad wiring connection. This was fixed and they sent me home.
Got home, tested it and it didn't work again.
I bought some led bulbs, fitted them and re-tested and it worked perfectly. Definitely a load issue on the vehicle side.
Took it back to jeep to FIX the problem. They spent hours and couldn't find the fault. They ended up fitting a relay to the brake wire which resolved the problem.
Am I happy about the fix, well not really. The underlying issue is not resolved, they just bypassed the issue and potentially adding another problem down the track.

[SeaComms]

OMG - thinking outside the box at a dealership - that is to be commended to start with!

It sounds like the load on the van is to high for the vehicle circuits, though I thought the later models actually installed relay control boxes so as the trailers lights did not put and extra load on the vehicle lighting circuits. On the JK its surprisingly just plug directly into the existing wiring loom paralleling the trailers lights so an overload in the trailer shorts out the vehicle lights...

[Cessa]

That is a good point of coming up with a plan B. Most highly regulated institutions don't dare muddy the water by doing something left field. but i'm sure Jeep Australia might have a different take on it.

The problem with the new WK is there is no plug and play loom for the trailer harness. You have to splice the harness into the existing loom.

I do see your point about the load in the van being too high to start off with. With that, it's a pretty new van and it worked perfectly with my Landrover. The auto sparky made a load tester to check the wiring on my car and it failed. He then checked 2 other cars (same type) and the tester worked fine. This determined that there was an issue with my car. The only test the dealership does is a continuity test on the points using an LED light tester. This unfortunately doesn't test real life loads.