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  #1033  
Old 07-26-2014, 01:53 AM
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Re: The Towing thread

Salmo you can find the reverse wire under the front side of the subwoofer where the loom runs over the wheel arch. Picture is here:

MY14 DIY Trailer Socket Wiring

Apparently "no one connects them". Great huh??

Cheers,
Steve
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  #1034  
Old 07-26-2014, 03:00 AM
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Originally Posted by Barboots View Post
Sorry guys, but I'm resurrecting one of the epic MY14 sub-topics... the "splice in" trailer wiring loom. Specifically, the connection for activating electric trailer brakes. I've read back until I glazed over, searched until I'd found Bob's signature text a thousand times, and reconsidered all that I knew previously.

The Scene:
- The brake switch switched wire on WK2s does not provide an adequate voltage to trigger the input on the P3, hence it is often connected to a brake light wire in the boot.
- The brake light circuit for a MY14 is different to previous models due to the lighting circuit to all brake lights not being commoned, but individual supplies from an ECU.
- If connected to one tail-light on a MY14, manual operation of the brake controller will not activate all of the brake lights.
- Operation of all brake lights under manual control is required by legislation.
- Commoning all the brake light circuits is likely to produce a sh!tstorm of errors from the brake light ECU.

I've read that using a relay on the brake pedal switch appears to be common. This slightly increases the complexity of a critical circuit, however routine testing should reduce the risk of getting caught out by failure at an inopportune moment. I've spent a while attempting to come up with an alternative solution using power diodes at the brake light feeds, but it quickly gets way out of hand... and nothing says that the ECU isn't going to see a series diode as a failed lamp.

Any comments and/or further ideas? Otherwise I guess it is to be a relay on the brake pedal switch...

Cheers,
Steve
Excuse my ignorance, im not familiar with brake controller's, however could you just parallel the brake light switch at the pedal with the manual over ride?

That should in theory activate the brake lights as though you had applied the brakes.
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  #1035  
Old 07-26-2014, 03:11 AM
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Re: The Towing thread

Yeah, that's not a ridiculous second option actually. Better than arsing around with trying to link but isolate the lighting circuits, that's for sure! It probably has a slightly higher degree of complexity than a relay on the input side, but moves the failure point to a lower risk area.

I'm going to have a good chew on that idea. Thanks

Steve
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  #1036  
Old 07-26-2014, 04:01 AM
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Just had a think about it. Under some conditions it might actually throw a code. I read in another thread that sone of the left foot braking folk out there were causing a service throttle code when taking off from lights. If wired as I mentioned the ECU could interpret an over ride as someone applying brakes. That is if you were accelerating at the time you were over riding...
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  #1037  
Old 07-26-2014, 07:52 AM
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Re: The Towing thread

Good point IBAJ... I'd forgotten that nuance of the "abuse" programming. I think you'd be correct in what you've suggested.

I'd also hit the wall with this idea in other areas. I doubt the braking system output would reliably switch a relay... it's a pretty "dirty" signal going to the brake solenoids from memory. Using the "trigger" wire (which also is what activates the brake lights in a perfect world) would actually result in a feedback loop, effectively latching the brake pedal switch on.

Pull in manual control. Brake lights come on. Voltage pulls in relay. Relay activates brake light switch. Brake lights come on. Number 9... number 9... number 9...

T'was a good thought but

I'll wait and see if anyone has actually had a meter on the brake switch and have some data for me. It's not clear from what I've read whether the signal is a problem for the controller due to low voltage or pulsing. I can't imagine it's CAN or digital, so either of the other two are workable.

I'd get my head under the dash and do some measuring but my neck hasn't been so great lately. That switch is in an awesome spot... not.

Cheers,
Steve
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  #1038  
Old 07-26-2014, 07:31 PM
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Re: The Towing thread

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Originally Posted by Barboots View Post
Anyone have a pic of a WK2 with a HR WDH on a HR bar?
Sorry Steve, I forgot about this.
Here's mine.



Cheers,
Matty
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  #1039  
Old 07-26-2014, 08:39 PM
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Originally Posted by Barboots View Post

Pull in manual control. Brake lights come on. Voltage pulls in relay. Relay activates brake light switch. Brake lights come on. Number 9... number 9... number 9...

My thought was a little different.

Both or either the brake light switch and override on the controller activate the brake light relay as they are wired in parallel.

Still have the issue of a possible service throttle code though.

Edit: Brake light switch should be 12v.
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  #1040  
Old 07-26-2014, 09:59 PM
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Re: The Towing thread

You'd have to draw me a picture mate... my brain isn't aligning with your suggestion. I keep seeing the problem I described.

I agree that the brake light switch should have 12V on it, but all the reports are that the signal is somehow problematic. I'm guessing it's either a logic level voltage ~5V, or pulsed for some highbrow reason. Plus there's the point you made about brake and throttle active simultaneously. I'm guessing it'd be safer to stay away from it.

Uh. New idea coming through. Gotta go.

Cheers,
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  #1041  
Old 07-27-2014, 01:05 AM
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Re: The Towing thread

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Originally Posted by Matty470 View Post
Sorry Steve, I forgot about this.
Here's mine.

Cheers,
Matty
Thanks Matty. I found a second hand Mopar bar for $200, so I couldn't help myself

The question of whether I'll use a WDH, and if so which one, remains. I'll probably take a few careful drives with the van on and assess how it goes.

Cheers,
Steve
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  #1042  
Old 07-27-2014, 01:19 AM
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Doesn't this give you all the info you need?

http://www.wk2jeeps.com/trailer/2014...ng_diagram.pdf
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  #1043  
Old 07-27-2014, 07:10 AM
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Re: The Towing thread

Only if you live in the States and order the towing package. Aussie JGCs don't have the module, so you'd still be wiring into the pedal switch. I did find one reference to someone who'd done this without a problem... but in a later post they said they hadn't towed... then later said it was actually wired to the brake light. Awesome.

Anyway the following is what I'll do. The only lamp which will not illuminate under manual control is the high mount. If I get pinged for this I'm obviously getting punished for something else!

Cheers,
Steve
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  #1044  
Old 07-27-2014, 07:22 AM
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Originally Posted by Barboots View Post
Only if you live in the States and order the towing package. Aussie JGCs don't have the module, so you'd still be wiring into the pedal switch. I did find one reference to someone who'd done this without a problem... but in a later post they said they hadn't towed... then later said it was actually wired to the brake light. Awesome.

Anyway the following is what I'll do. The only lamp which will not illuminate under manual control is the high mount. If I get pinged for this I'm obviously getting punished for something else!

Cheers,
Steve
That diagram won't work as you have drawn it. You need to have the P3 trigger to the relay coil where you have "Centre".
Also, what are you referring to as "centre"? Thay way the "trigger" the relay. Unless im misunderstanding the trigger wire from the P3.

The diodes need to go on the factory wiring, but I think you know that already. I remember reading that the other day.
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