Jeep help needed.

[MickinOz]

People, I received a call from my son who is an electrical contractor.
By electrical contractor, I mean he works on 240v house wiring, shops, commercial, industrial, camera systems, etc.
But today, he was persuaded to look at his mate's 2015 Australian delivered Jeep Grand Cherokee.
A towbar kit for this thing was $2500 plus fitting, so the guy bought his own tow hitch setup cost $400 from the states. But, no lights.

So he got a fancy pants plug and play loom. Just plug it all together and be happy, right?
Nope, None of it is working and after taking a look, my boy phoned a friend. Me.

The plug'n'play loom has these connectors where you unplug a tail light, plug in your "piggyback" loom and plug the vehicle wiring back in.
Like this:

piggyback connection for trailer loom.JPG (41.47 KiB) Viewed 247 times

Hope that makes sense.
So there is a piggy back connector for brake, tail light and left and right indicators.
These feed into a little black box that furnishes 4 lines out: earth, tail lights, left brake/indicator, right brake/indicator.

i.e. standard 4 pin US trailer socket that flashes the brake lights for indicators.

Edit: Note that it is piggybacking off the rear lights, it hasn't been plugged into a socket that needs activating via an ECU re-flash.

From there he has plugged in another black box which is designed to convert standard US 4 pin to Euro 7 pin, splitting the brake/indicator functions apart again.
Of course, the whole shebang doesn't work. At the 4 pin out from the first black box, we can measure ground, tail lights, and right and left brake lights. The right and left brake lights do not not flash if one or the other indicator is turned on.

I looked at it and did a few basic tests. In consultation with my son we came to the conclusion that perhaps the first little black box, the one that combines individual brake and turn signals, isn't functioning as intended.

My son has had the covers of these black boxes and they are "potted". i.e. the circuitry has been completely encased in some sort of resin. Totally unserviceable/untestable.

Basically what this guy has done, using plug'n'play kits, is take individual Australian lights, combine them to 4 pin multifunction US trailer lights with combined brake light/turn signals, convert that to 7 pin Euro spec that splits the brake lights and turn signals, then plug in an old Australian 7 pin trailer and find it doesn't work.

Dunno about you guys, but I am less than surprised.

Anyway, assuming that there is no magic silver bullet "ah ya forgot to do this" solution, my question is this:
Can you take all this out and do it Ol' Skool?
I.e. grab yourself some 7 conductor trailer cable and some scotch locks and tap off each individual light, and run that to a socket wired in accordance with Australian 7 pin wiring.
i.e. get rid of two convertors and simply power the trailer lights direct like the good 'ol days?

I ask, not because it is complicated (I could wire it in my sleep I reckon), but because this $80,000 Jeep is running all LED lighting and I'm not sure what the circuitry can handle; nor whether the flasher circuit will get upset if extra load is applied.
The first black box is powered from the battery, leading me to think there might not be much extra load on the wiring to the vehicle lights.

Keen t hear what people do.

[Tom&Shelly]

Anyway, assuming that there is no magic silver bullet "ah ya forgot to do this" solution, my question is this:
Can you take all this out and do it Ol' Skool?
I.e. grab yourself some 7 conductor trailer cable and some scotch locks and tap off each individual light, and run that to a socket wired in accordance with Australian 7 pin wiring.
i.e. get rid of two convertors and simply power the trailer lights direct like the good 'ol days?

I ask, not because it is complicated (I could wire it in my sleep I reckon), but because this $80,000 Jeep is running all LED lighting and I'm not sure what the circuitry can handle; nor whether the flasher circuit will get upset if extra load is applied.
The first black box is powered from the battery, leading me to think there might not be much extra load on the wiring to the vehicle lights.

Keen t hear what people do.

I don't know about all LED lighting for Jeeps--ours is a 2009 so all incandescent. So I would rig up an incandescent bulb to one of the circuits with a minimum of effort, and try it. Can't imagine it would do any permanent damage to the Jeep. If it blows a fuse, then I would assume they sized the fuse that way for a reason and do a re-think, but I would imagine they designed the trailer lighting to handle a trailer with incandescent lights...

Of course, I can't assume any liability for this advice. Just what I would do.

Tom

[pchast]

Here in the US I found the wiring for led lights is so fine, i guess 20 gauge or smaller, On the car I worked on( a VW EOS). It can't carry the power to run 'extra' lighting.

Its the reason for a unit to sense the indication. It must use a separate power source to provide the 'extra' lighting of the trailer.

[H.A.]

Had you researched if Jeep has a Bodybuilders Guide ?
I’m well versed with Toyota and Ford, I would expect Jeep has similar Body Builder documents. There is always a section on maximum current available for alternative or additional lighting, wiring colours, etc.
As aside..
Respects to Australia adopting the Euro-Japper tail light wiring scheme.
For all the tail light headaches people experience. N.America has to the biggest load of dipshitz when it comes to tail light systems.

[MickinOz]

The US does seem to have quite a mish mash of wiring schemes. How your houses function is beyond me.
Nah, not really, just joking.
There's a reason for your multiple systems, I think.
It's because in many things electrical and mechanical, America was (still is) an innovator and early adopter.
So there are many legacy early systems that still need to work, despite being superseded by more modern and perhaps more universal systems.

I think the client didn't really understand what he was attempting when he chose the system he purchased. The big attraction was the plug and play aspect, I think. Its just that it didn't work.

[Tom&Shelly]

How your houses function is beyond me.

Well, usually they don't very well. And then you throw in the executive branch and...Oh, wait, you're talking about our homes! (Non-partisan folks!)

Seriously, I was stationed in England as the "site electrical engineer" on a US Air Force communications base back in the 1980's. (Actually an RAF base we "borrowed" or leased, or something.) Parts of my bailiwick (a word I learned while there, btw) were the US 60 cycle power system, and the base 50 cycle system, the latter being part of the island's power grid. My office was in a World War II era building and had one of the "old style" outlets (red and black wires) while much of the rest of the base had the more modern outlets with blue, brown, and green/yellow wires. Those were the 240 vac lines. (Each plug for those came with its own fuse!) Then there were the buildings with "tech" power: Good old American 120 vac with 60 cycle power. Except we were such a small grid, that it generally ran anywhere between 55 and 65 cycles. (I kept an electric clock plugged in at my office so I could suggest to the sergeant who ran the power plant when it was time to tweek the generators.) Oh, then down the street, on another base, my bachelor officer's quarters had transformers to convert 50 cycle to 120 vac, so we could use appliances (except clocks) with our American plugs.

But most of that is beside the point. Here in America, every few years they upgrade the power distribution standards, but older homes are generally exempt, unless and until they're sold or other major modifications are done. The story in England, I understand from talking with the more knowledgeable engineers there, was that so many buildings were bombed out during the WW II blitz, that after the war they designed a major upgrade to their power systems, and mostly did it all at once. (Of course, the MOD itself was exempt, which is why we had two different English standards going at once.)

After returning to the states, I rented or owned a half dozen different houses at different times, and the electrical issues there paled in comparison. (Well, okay, I did rent one house built in the 1940's with a single 10 amp fuse for the kitchen. But who wants to run the micro-wave and the toaster at the same time anyway?)

Tom

[MickinOz]

The change from red/black/green (or even bare earth wire) happened here, too.
The idea is that brown/blue/yellow and green better guards against incorrect connections by colour blind people.
My son is an electrical contractor, and it's amazing how many rolls of cable are red/black/yellow and green still.
Anecdote: a while ago a very expensive truck wash station was scrapped at my work.
The engineer who purchased the "turn key package" was unfamiliar with the difference between power supplies here and in the US.
Step down transformers were considered but the frequency difference meant the pump motors would turn too slow.
Changing out motors and modifying the control systems was also considered.
In the end neither idea got past the extra expense.