Featured Annoying euro system - Peugeot RCZ with JBL factory upgrade

[RCZ-mad]

HI all, I'm no electrician and I'm trying to figure out this system as I want to fit new speakers etc.

The Peugeot RCZ had an option of a JBL upgrade which consisted of the following;

1. 2 x front tweeters (dedicated wires, with a capacitor for passive filtering)
2. 2 x 6.5" fronts with dedicated wires
3. 2 x 6"x9" rear speakers with tweeters integrated (there are 4 wires going to each one, I assume two for the main cone and other two for the tweeters?)
4. 1 x JBL amp in the boot

The head unit has wires that route to the JBL amp which is in the boot (that's in the center with three plugs), and then from the amp, wires go to all of the speakers (there are some other wires such as ground wire and some others I don't know what they do).

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.

So looking at the wires in the plugs at the amp, I then tested to try and identify which wires were the ground wires for the speakers. But,
every single wire on the white and blue plugs gives me a voltage reading of around 5.4v, 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 one supposed to be a ground wire? This doesn't make sense! Any experts can figure it out?

Click to read more...

 

[CarAudio.com - Hal AI Bots]

HI all, I'm no electrician and I'm trying to figure out this system as I want to fit new speakers etc.

The Peugeot RCZ had an option of a JBL upgrade which consisted of the following;

1. 2 x front tweeters (dedicated wires, with a capacitor for passive filtering)
2. 2 x 6.5" fronts with dedicated wires
3. 2 x 6"x9" rear speakers with tweeters integrated (there are 4 wires going to each one, I assume two for the main cone and other two for the tweeters?)
4. 1 x JBL amp in the boot

View attachment 65103

The head unit has wires that route to the JBL amp which is in the boot (that's in the center with three plugs), and then from the amp, wires go to all of the speakers (there are some other wires such as ground wire and some others I don't know what they do).

One plug is black, one is white and the other is blue, as below:

View attachment 65104

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.

So looking at the wires in the plugs at the amp, I then tested to try and identify which wires were the ground wires for the speakers. But,
every single wire on the white and blue plugs gives me a voltage reading of around 5.4v, 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.

View attachment 65106

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

View attachment 65107

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

It looks like you're diving deep into understanding the JBL upgrade system in your Peugeot RCZ. Let’s break down how the wiring might work.

### Understanding the Wiring:

1. **Speaker Configuration**:
- **6"x9" Rear Speakers**: If there are four wires going to each speaker, two wires are likely for the main cone, and the other two for the tweeters. This is common in systems with combined speakers, where each driver has separate connections.
- **Ground Wires**: Each speaker does indeed need a connection back to ground. In many setups, the ground can be shared among multiple speakers, so not every wire going to the speaker has to be a separate ground.

2. **Wiring from the Amp**:
- Generally, the amplifier will send a positive signal wire to each driver (cone and tweeter), while a common ground may be used for return paths. This way, multiple speakers can share ground connections, reducing the number of wires you need to run through the vehicle.

3. **Capacitor for Tweeters**:
- The capacitor you mentioned for the tweeters acts as a high-pass filter, allowing only high frequencies to reach the tweeters, while blocking lower frequencies that could damage them.

### Troubleshooting Steps:
- **Testing the Wires**: Using a multimeter, you can identify which wires are positive and which are negative for each speaker.
- **Inspecting Connections**: Check the amp connections to ensure there isn’t a loose wire and that proper wiring schematics are followed.
- **Manuals and Diagrams**: If you can find a wiring diagram specific to the JBL system in the RCZ, it could provide clarity on which wires are used for the tweeters and which are ground connections.

### Summary:
In such systems, the design can look deceiving, but that’s often how manufacturer setups can consolidate wiring effectively. If you’re putting in new speakers, ensure that they match the existing wiring in terms of impedance and power handling to avoid issues.

If you have any specific questions about wiring or speaker choices, feel free to ask!

 

[1aespinoza 10+ year member]

Any experts can figure it out?

Three ways you can fugure this out is: 1) look up Peugeot RCZ amplifier pin-out. 2) use an analog multimeter set to ac volts, play a bass note and when the needle jumps forward, the terminal on the red test lead is the positive. 3) touch a 1.5v or 9v battery to the speaker. When the cone jumps outward, the terminal on the positive side of the battery is the positive.

 

[RCZ-mad]

Three ways you can fugure this out is: 1) look up Peugeot RCZ amplifier pin-out. 2) use an analog multimeter set to ac volts, play a bass note and when the needle jumps forward, the terminal on the red test lead is the positive. 3) touch a 1.5v or 9v battery to the speaker. When the cone jumps outward, the terminal on the positive side of the battery is the positive.

1 - Yes that is the best answer but I should have mentioned, I've already tried to find this information and its the industries best kept secret lol can't find it anywhere!

2 - I'll try that but to clarify, if I set the multimeter to AC, where am I putting the test leads? I assume red to what I think is the positive, and black to ANY ground point is ok?

3 - I might get to that last, as the amp is easily accessible in the boot, but the speakers have a bunch of trim to remove which I want to avoid for now if I can.

Thanks for the suggestions!

 

[1aespinoza 10+ year member]

I'll try that but to clarify, if I set the multimeter to AC, where am I putting the test leads? I assume red to what I think is the positive, and black to ANY ground point is ok?

The leads will go into the amplifier's output using the color coded sets. As stated above, you will assume the red wire and the gray wire are a set, so trace that on to the amp output and test them as a set. From experience I can state that American OEMs do not care about the color they use as positive and negative.
You may also want to unplug the output terminal at the amp and test resistance. See which sets give a reading. Each reading will be a voice coil.

 

[RCZ-mad]

The leads will go into the amplifier's output using the color coded sets. As stated above, you will assume the red wire and the gray wire are a set, so trace that on to the amp output and test them as a set. From experience I can state that American OEMs do not care about the color they use as positive and negative.
You may also want to unplug the output terminal at the amp and test resistance. See which sets give a reading. Each reading will be a voice coil.

Yes that is the confusing part, because I've tested the red and grey set, both give same reading. I could be doing it wrong, or I could be testing the wrong wires, but its not making sense to me. I've checked every single wire coming out of the plugs on that amp, and they all read the same except one wire which is the thickest...a green wire with yellow stripe (which I assume is the ground wire for the amp itself).

 

[1aespinoza 10+ year member]

Yes that is the confusing part, because I've tested the red and grey set, both give same reading.

The plot thickens.
When testing, were the harnesses unplugged from the amp?
You mentioned difficult speaker access; is there an easy one you can test directly?

 

[RCZ-mad]

The plot thickens.
When testing, were the harnesses unplugged from the amp?
You mentioned difficult speaker access; is there an easy one you can test directly?

No, the plugs were left in. For the red speaker wire, I touched it with the red multimeter test lead. For the ground black test lead, I had that touching the ground wire also on the amp (green with yellow stripe).

Is that not a good way to test?

 

[1aespinoza 10+ year member]

No, the plugs were left in. For the red speaker wire, I touched it with the red multimeter test lead. For the ground black test lead, I had that touching the ground wire also on the amp (green with yellow stripe).

Is that not a good way to test?

That is a good way when testing power supply. What we first want to find is which wires are sets, then we want to know polarity, and right after that we want location (right rear). Leaving the harness plugged in will give erratic circuit readings instead of voice coil, so it must be unplugged. If the tweeters have an inline capacitor, the readings will also be off, but we will cross that bridge when we get there.

 

[RCZ-mad]

That is a good way when testing power supply. What we first want to find is which wires are sets, then we want to know polarity, and right after that we want location (right rear). Leaving the harness plugged in will give erratic circuit readings instead of voice coil, so it must be unplugged. If the tweeters have an inline capacitor, the readings will also be off, but we will cross that bridge when we get there.

Here is a really primitive sketch of the system...I know the amp is wired on the CANBUS, as anyone who has tried to put in an aftermarket headunit has found out, the amp won't go on as the aftermarket unit isn't able to talk to it and there are no aftermarket harnesses available that work with the JBL units.

So, I've added the ECU in there, but accuracy may vary lol.

Also, I managed to get a hold of 'Service Box' software for the RCZ which has wiring diagrams but no surprise...has everything EXCEPT the JBL system wiring. It has the satnav version though, but that is no good.

I still don't understand what you mean by 'leaving the harness in will give erratic readings'. If I unplug any plugs in the amp, then there is no power going over those wires, so testing will tell me nothing. Which means I would have to test the prongs on the amp where the plugs are placed over normally...is that what you're saying? I mean, if that is, then how would it be any different to leaving the plugs on? The prongs in the socket provide power to the wires in the plugs, so testing the prongs or testing the wires would be the same thing surely?

 

[RCZ-mad]

Ok I managed to find the wiring schematic for it. Its for the satnav system but really looks like the same setup as the JBL...Even if it isn't the JBL amp, I would imagine they would use the same wires and harness for the speakers in the JBL system. SO working on that assumption, this wiring diagram should apply to my system...but, I'm not an electrician so trying to decipher this is a challenge lol.

Any experts can read this easily and give any suggestions? I've highlighted the amp in red and also highlighted each plug according to their actual color.

Also, I've been able to match up what my own investigations were regarding which wires go to the speakers, I at least know that much. So for instance, on the blue plug, I found that position 4 and 12 were for the main woofer on the rear right speaker, and position 6 and 14 were for the rear right speaker tweeters. BUT, the damn diagram still doesn't tell me what wires are ground wires! That's all I need to know

And focusing on one speaker in particular, the RH Rear, this is the wiring for it:

EDIT: just found the wiring color key, so does this mean we can figure out what is the ground wires? Strange thing is, I don't think this is all of the information on the wiring in the car, because there are green wires with yellow stripes, plus also salmon pink wires and those colors aren't shown here...

 

[1aespinoza 10+ year member]

Any experts can read this easily and give any suggestions? I've highlighted the amp in red and also highlighted each plug according to their actual color.

Holy moly! These techs do NOT know how to simplify anything! Probably done on purpose. That jargon is out of my scope of deciphering.

I still don't understand what you mean by 'leaving the harness in will give erratic readings'. If I unplug any plugs in the amp, then there is no power going over those wires, so testing will tell me nothing.

My bad, I was too vague on this part. After disconnecting the harness that goes to the speakers, you will prod the harness pins to find which wires are "pairs". Each pair will be a speaker. You will use the Ohms setting for this test.

 

[RCZ-mad]

Holy moly! These techs do NOT know how to simplify anything! Probably done on purpose. That jargon is out of my scope of deciphering.

My bad, I was too vague on this part. After disconnecting the harness that goes to the speakers, you will prod the harness pins to find which wires are "pairs". Each pair will be a speaker. You will use the Ohms setting for this test.

Ok so I set the multimeter to the Ohms setting, then I prod the harness pins to find the "pairs"....but what output am I supposed to see on the screen that indicates a pair?

 

[1aespinoza 10+ year member]

Ok so I set the multimeter to the Ohms setting, then I prod the harness pins to find the "pairs"....but what output am I supposed to see on the screen that indicates a pair?

Around 4 Ohms, which is what the majority of car speakers are.

 

[RCZ-mad]

Around 4 Ohms, which is what the majority of car speakers are.

Ok did that and identified the pairs (already pretty much figured it out earlier by matching wire colors and position, but this confirmed).

So then that leaves identifying ground wires.

Is there a way of identifying which one of the pair is a ground wire, by using the multimeter and touching the prongs? Some setting on it, or perhaps turning the sound system on and probing then?