JBL amplifier wiring

[RCZ-mad]

Hi all, I wanted to put in one of those under seat subwoofers, so I have to deal with the dreaded JBL amplifier.

The plan is to connect it like so:

1. Place subwoofer under driver's seat.
2. Run yellow wire from subwoofer to the battery for power.
3. Using spk connection method (not RCA), tap into the rear speaker wires at the JBL amp for the sound signal.
4. Finally, tap the blue remote wire into an applicable wire at the JBL amp for signalling sub on and off.

Since the JBL amp is located in the boot, and all speaker wires etc. come from there, I should be able to intercept the wires I need there instead of messing about around the head unit.

I've sorted the blue remote wire for the sub as I found someone who had identified which wire going to the JBL turns on and off with the lock/unlock, but they never mentioned the speaker wires.

So I just need to know if anyone either has the wiring info for the plugs on the JBL amp or happens to know which exact wires are going to the rear speakers?

I could of course figure it out by removing the rear trim and rear speakers so I can see the wiring colours and then match it up at the amp, but I'd rather avoid pulling the interior apart if someone has already figured it out, plus I want to know what all of the wires are for so I don't have to guess when I do any future upgrades.

I imagine someone, somewhere in Europe has already figured this thing out!

Took a photo earlier, not great but gives you an idea what I'm talking about:

 

[RCZ-mad]

So I did a bit of investigation on the wires coming from the plugs in the JBL amp.

I'll preface this by saying, I am not an electrician so I may not be accurate and I may not be explaining things properly, but I'll give it a shot.

Essentially, there are three plugs with an assortment of wires in each that are plugged into the JBL amp in the boot. One plug is black, one is white and the other is blue, as below:



Looking at the 4 wires going into the 6"x9" rear speakers (I assume two for the main woofers, two for the tweeters), I wrote down the colours. Then I noted down the colours of the wires in each of the plugs (I didn't do the black plug, that appears to be wires for general purposes, for instance it has the thickest wire coming from it that is green with a yellow stripe, which should be the ground wire).

As far as I can tell, the white and blue plugs are each mainly dealing with the left and right sides for the most part.

When I matched up the wire colours, I could see that the white plug has wires in it from the left rear speaker (four wires in total), and some other wires to be determined.

The blue plug has wires for the right rear speaker (also four wires in total), but also appears to have wires for both of the front tweeters (remember, the head unit sends all signal to the amp in the boot, and then wires for all of the speakers come from there).

I wrote down the wire colours, positions and what they are attached to, see below.

However, with all of that done, I realised I don't actually know which speaker wires are positive and ground. I could take a good guess, for instance one of the speakers has a red wire and a grey one paired...so I would assume they would never have a ground wire coloured red, so the grey must be ground.

If anyone is good with electronics and wires, have a look at what I wrote and happy to hear any corrections or feedback! The colours were one of the tough parts, as a lot were similar.

 

[RCZ-mad]

I just tried to identify the ground wires for the speakers in these plugs...every single wire on the white and blue plugs gives me a voltage reading of around 5.4v, what the hell is going on? They can't all be giving power lol any ideas what is going on?

Just to show I have the right wires, here is a picture of a rear left speaker, it has 4 wires....reddy orange, grey, salmon pink and yellow.



Those wires correspond to 4 wires on the white plug, in the red square below:



So how can all four of those wires going to the speaker be powered? Isn't at least supposed to be a ground wire? This doesn't make sense