JDM center garnish brake light wiring?

Hey, first time poster looking for some info about weird regional changes;

 

 

I've recently scooped up a set of JDM tails for my Liberty (AUDM Legacy) wagon as mine were pretty beat, got around to installing just the garnish and realized that the additional (4th?) brake lights don't work because AUDM cars have different wiring; so my question is - is there any (reasonably) easy way to make them work?

 

 

If you're unfamiliar with AUDM cars, for whatever reason they have the physical sockets+bulbs there (alongside a different housing), but they don't actually work. I've tested the foglight switch/signal (or in my case, the blocked off plug ) and confirmed they get a signal - they just don't actually turn on... I've tried my reverse light bulbs in them which I know work and still had no luck. The actual harness that runs into the roof only has 3 wires (ground, fog and reverse, seemingly) whereas the JDM garnish has a 4th wire which I can only assume is the running light+brake signal. Short of tapping into a wire from a corner light, the only thing I can really think of is wiring them into the number plate lights and making them running lights, which would be fine, but I'm hoping there's a less dodgy way of going about it.

 

 

Apologies in advance for the slight wall of text

Edited May 6, 2021 by dylanSN

Could you possibly send a pic of the back of it so we can see what you're looking at? It should be pretty easy to add another bulb. I would think it's be easiest to use the non JDM harness and then splice in another socket onto whichever light you want to trigger it.

Yep, here's a couple of the JDM garnish;

 

 

And a couple of the stock one;

 

Sorry about the blurriness of the last one, regardless, I'm clueless lol - even the stock garnish colours don't correspond.

Oh I see, I was thinking there was an extra bulb, not an extra pin. I would just plug it in and go on your way. I would guess the JDM cars have an option to use the reverse lights as rear fogs. Either way, it should work when you plug it in, or you can use the wiring from the AUD center section. If you want to do some experimenting, you can put a single spade connector into the male side of your AUD plug and ground it to see what turns on/off on the JDM light. And then if it does something you like, you can run that to an auxiliary switch.

I think we're confusing eachother somewhat lol, the issue I'm faced with is for whatever reason the brake lights don't work (even with the original garnish, I've never actually seen any BG here with those lights functional), seems to be a weird regional thing. For whatever reason AUDM cars (wagons at least, pretty sure sedans are the same though) only have 3 brake lights; the 2 corners and the top one - despite having the sockets and bulbs in place.

 

 

Whatever the brown wire on the car side harness is supposed to do (the ones that run to the brake light), it doesn't do - so the additional brake lights don't do anything. I've taken off some of the tape on the far end of the harness as I hoped the 4th wire would be tucked somewhere there but it doesn't appear to be the case. I've had it plugged in for a little while now, reverse lights work fine, just the wire running to the brake light does absolutely nothing, even with my non-existent foglights turned on.

 

 

All I can really think of is cutting the brown wire and running the number plate light into that pin and just hoping they aren't super bright and calling it a day, though obviously if I can get proper brake light functionality I'd much prefer that.

Oh I think I understand. I wonder if Aus has a rule about brake lights being on a panel that opens. US has a rule like that about turn signals not being allowed on panels that open such as tailgates/hatches. If you want them to operate as brake lights/running lights. Your best bet would be to track the colors of the wires back to the C pillar and tap them into the wiring for the corner lights.

Yeah I'm not sure, wouldn't doubt something silly like that, regardless I've seen numerous vehicles with brake lights on the hatch/boot alongside the body which were seemingly completely stock so I can't see it ever being an issue.

 

Any idea where exactly the easiest point to tap in would be (as in what it's hiding behind) and what exactly it'd entail? my main concern is having to run it through to the hatch which sounds like a pain, and would probably mean dropping my headliner which I'm not too keen on.

 

I figure the sole line/pin that runs to the brake light must be a ground? it's the only wire running to the brake light and the fog switch did nothing, so surely I should just be able to tap into a plate light and wire that to the 4th wire (unpinned one) on the cluster harness?

The plastic trim around the rearmost windows needs to be removed to access the wiring. It's all loomed up so you would have to remove some of the loom to find the right colors to access. For example, the two wires running to the center garnish are brown and yellow, the corner wires are brown and red. You can figure brown is either common ground or common power. Find those 3 wires in the c pillar, use a multi meter to determine what is what and then then splice the yellow into the red to get power to the center lights. These colors are arbitrary, I don't know the actual colors

Seems straight forward enough, I don't suppose you know whether dropping the headliner is necessary? I'll need to pull off the C/D pillar trim pieces anyways to install the corner lights, so if I don't need to drop the headliner I'd might as well do it properly, thanks a bunch for the help by the way - I'd have no doubt done something dodgy without your help haha.

You don't have to drop the headliner to access them, once you remove the rear window trim you will have all the access you need.

Sweet, sounds like a plan - thank you again for the help.