Evening all,

(I did try a forum search first, but didn't find anything in the first couple of pages of results).

My car (2000 4.0L 'base spec) came to me with an aftermarket stereo - a Sony radio/ CD player. However while it plays OK in the front doors, there's no sound in the back.

In my internet wanderings about P38s I thought I'd seen something about the radio install not being as straightforward as unplugging one and swapping in another, but I can't find anything which outlines the basic issues or any options.

Can anyone point me in the direction of this sort of info?

(It probably isn't the most important thing I should be thinking about - but you've got to start somewhere!)

Ta

Donald

I think it depends on the spec of what is already fitted. If you have the basic setup with no factory fitted amplifiers then I believe you can plug straight in. If you have factory fitted amplifiers (which I believe the majority were ordered with) then you need an adapter to go between the head unit speaker outputs and the vehicle loom. You can spend a bit of money on a ready made on in a neat little plastic box (which I have to admit I did) or make one yourself.
Others will no doubt be along shortly to guide you on this.

If you have the low line system, you'll have 6.5" woofers in all 4 doors with tweeters in the front. Tweeters have a capacitor on the back of them to block the low frequencies and are connected in parallel with the woofers. In this case the plug on the loom will be a standard DIN 8 way plug that will plug straight into the speaker socket on a standard head unit. The mid line system has the same as the low line system but adds midrange speakers in each door, still in parallel with the woofers and again has the 8 way plug. The High line system adds the steering wheel controls, amps in each door (so attenuators are needed to drop the speaker level output from a standard head unit down to a level suitable for the amps) and the sub in the LH side of the boot. The amps incorporate a crossover network so feed the woofer from one output and the midrange and tweeter from the other. The high line has a 10 way plug on the loom as it has the sub output as well as the 4 speaker outputs so won't fit into a standard head unit (which normally use separate phono sockets for a sub output).

So, if you have the low or mid line system, you can plug the speaker plug into a standard head unit and it will work fine (which is what I have). Originally my car only had the Low line install but I changed the door panels for ones with the midrange speakers so upgraded it to the mid line install. Unless whoever installed yours has been playing with the wiring, which they shouldn't need to do, then all 4 channels should work fine. However, the woofers do have a habit of seizing meaning they can't move so even if it has been wired correctly, you'll get no noise. In which case, see the upgrades thread and get yourself a pair of JBL Stage 600CE speakers for the front and put the existing front ones in the rear.

Thanks very much guys. After posting the first message I had a further google and became quickly more confused (and discouraged..). However what's here is more straightforward.

I never thought to mention the lack of steering wheel controls and, as far as I can tell, no mid-range speakers in the door cards. Which does suggest a 'low line' system. I'm completely fine with that to be honest, especially if it makes installing or working on it more straightforward.

So, the back door speakers not working could be:
something wrong with the installation (haven't had a look yet - Defender still hogging the garage)
the speakers themselves being broken
or, a break in the loom somewhere between the radio and the rear speakers.

This gives me a good steer for when I get a chance to look at this.

Ta

Mid range speakers are pretty obvious, as they have their own cloth covered grille above the grille for the woofers. Speaker feeds also go via a multiway connector behind the LH kick panel although it would be a bit of a coincidence if only the feeds to the rear speakers had gone green and hairy and neither of the feeds to the fronts.

Gilbertd wrote:

Mid range speakers are pretty obvious, as they have their own cloth covered grille above the grille for the woofers. Speaker feeds also go via a multiway connector behind the LH kick panel although it would be a bit of a coincidence if only the feeds to the rear speakers had gone green and hairy and neither of the feeds to the fronts.

Updating this as I now have a little more info.
It is a mid range install - I just hadn't noticed the additional speaker cover.

I was able to have a look at the install yesterday, as I was pulling out the HEVAC controller anyway. It's a pretty basic Sony unit that's in there - no sub outlets or anything - just the aerial coax, and the ISO plug link from the unit to the car wiring. I couldn't see anything wrong with that at all.

So - when you say the LH kick panel - is that the one I'd have removed to get access to the HEVAC screws? Or is it something on the other side of the footwell? i.e. adjacent to the door/wing?

Once I get my window switch panel back I suspect I might be having to go into the doors anyway to check out the mechanisms, so that would be a good opportunity to investigate the speakers.

Ta.

Panel where the bonnet release is. Both sides have speaker wires running through them afaik.
White multiplug but be careful as you may need to strip and solder them as they corrode.

Thanks for the reply!

I figured this out kind of by default. I had the panels either side of the centre console out, to remove the HEVAC controller - no wires under there. Then I took the LH kick panel out while I was working on the heater blower and found a few bits of the loom.

Without disturbing things at all, everything looks pretty good in there. Nothing that would make me think there was any corrosion or the like.

Which does point more towards the 2nd row speakers. I'll need to take the RH driver's side off shortly to see if I can figure out why the window isn't working - and that will be a good opportunity to check out the speakers too.

Can you take a picture of the connectors at the head unit? The connectors on the post '99 are different to pre- '99. pre '99 had a 10 way pink connector, which has the 4 door connections and the sub wires aswell. Post '99 they changed it so there's an 8 way ISO connector for the doors, and then there is a separate set of mini-ISO connectors which the CD changer plugs into the factory head unit with AND the subwoofer output is fed from here too.

If it's a mid/high line spec vehicle then I would expect there to be 8 wires coming out of the main ISO connector - 2 for each door, and more than likely have amps in each of the doors. The premium (DSP) system only had 4 wires coming out of the main ISO connector as a left/right feed, which was then split to the correct doors by the DSP amp, but this was pretty much only on the vehicles with factory navigation.

The easiest way to identify what system you have would be to pop a door card off and get a picture or 2 of what's in there and also a picture of the connectors at the radio.

Marty

Gilbertd wrote:

If you have the low line system, you'll have 6.5" woofers in all 4 doors with tweeters in the front. Tweeters have a capacitor on the back of them to block the low frequencies and are connected in parallel with the woofers. In this case the plug on the loom will be a standard DIN 8 way plug that will plug straight into the speaker socket on a standard head unit. The mid line system has the same as the low line system but adds midrange speakers in each door, still in parallel with the woofers and again has the 8 way plug. The High line system adds the steering wheel controls, amps in each door (so attenuators are needed to drop the speaker level output from a standard head unit down to a level suitable for the amps) and the sub in the LH side of the boot. The amps incorporate a crossover network so feed the woofer from one output and the midrange and tweeter from the other. The high line has a 10 way plug on the loom as it has the sub output as well as the 4 speaker outputs so won't fit into a standard head unit (which normally use separate phono sockets for a sub output).

So, if you have the low or mid line system, you can plug the speaker plug into a standard head unit and it will work fine (which is what I have). Originally my car only had the Low line install but I changed the door panels for ones with the midrange speakers so upgraded it to the mid line install. Unless whoever installed yours has been playing with the wiring, which they shouldn't need to do, then all 4 channels should work fine. However, the woofers do have a habit of seizing meaning they can't move so even if it has been wired correctly, you'll get no noise. In which case, see the upgrades thread and get yourself a pair of JBL Stage 600CE speakers for the front and put the existing front ones in the rear.

Hi there, this comment has helped me massively, can I ask you three more questions:

I have the low/mid line setup, no amps on any of the doors.

Currently my Sony head unit is plugging in fine, the front speaker outputs seem to be powering all 4 doors though (front and back). Is there a way of correcting this as my head unit has 55W per channel if I can make use of all 4 channels (front left / right, rear left/right), this would help as I’m planning to upgrade all the speakers in the doors. Alternatively, I was thinking I could adapt my iso adapter to bridge those outputs from the head unit so that 110w of rms is coming out of each of the channels, to compensate what arrives to the speakers?

Second question - do you know of any powerful mid range speakers to replace the factory fitted ones?

Third question - it would be ideal if I could somehow just get a feed direct from my new head units and then be able to fit my own crossovers in the doors as it suits me. Currently the cables coming out the doors are already specifically low / mid / high, is there a way of getting just normal full range to the door? I don’t know where in the car the cable is being split into 3 and crossed over, do you? If I knew that then I could rewire at that point rather than have to run new cable

If your Sony unit uses standard DIN connections, you should have two plugs, both 8 way, with one supplying the power connections while the other has the 4 outputs (see https://en.wikipedia.org/wiki/Connectors_for_car_audio#/media/File:ISO_10487_connector_pinout.svg). This means that each of the 4 channels is separate and output level on each is dictated by the balance and fade controls on the head unit. The same 4 channels are fed to each door where, on a low or mid line install, they arrive at the door as a single pair and split inside the door to feed the 3 speakers in the front doors (and the 2 in the rears). No crossovers on these systems but easy enough to install passive crossovers inside the doors.

Can't help with replacement mid range speakers without knowing what size they are but you should be able to find something. The JBL speakers I fitted in mine are obsolete but have been replaced with the Stage 604C which come with a crossover anyway, see https://www.amazon.co.uk/JBL-STAGE2604C-2-Way-Component-System/dp/B07QH6BXPY/

Resurrecting my own thread it appears - with apologies for being AWOL for ages. On the plus side the P38 just keeps on keeping on.

When I got my black (“Ash grey”) interior it came with door cards. They became “in the way” apparently, so I started swapping over today - the first time I’d taken the originals off to see behind them. I was 99% certain that my car had no amplifier in the boot but have checked this again, and I now know that there are no amps in the doors. Highline BECM, but Lowline front door outstations. 10 speaker install with 3 in each front door and 2 in the each rear door. I think this means everything should be easier - but what do I know!

One of the large rear speakers is gone (tested in 2 known working locations) so I’ve swapped in the working ones from the front into the back doors. I will be getting new speakers for the front - quite probably the JBL ones, but….

I don’t seem to be getting anything from the mid-range speakers in any location, and fairly sure the tweeters in the front doors are also doing nothing at all. I’ve read the point about the bass speakers rusting and stopping working. Does this affect the mid ones too? It’s just a bit puzzling that they would all go. To my mind it points to something else but I don’t know what?

Is there another part of the system that’s hidden behind the dash somewhere? (Edit - after further googling/reading - I feel there must be “something” I’m missing? Otherwise how do the bass/mid/tweeter speakers get the appropriate signal??)

To recap it’s a Pioneer head unit, that replaced the Sony one in the car when I bought it. I never had or even saw the factory one.

I feel a bit of a “cheat” not contributing anything for ages and then coming straight back with a question, but I do appreciate any help.

Thanks

Righty-ho! In the interests of providing as much info as possible, and helping myself, I've been out with the multi-meter...

All 4 mid-range speakers in the old door cards are testing OK - between 3.3 and 3.5Ohms. Confident I'm not futzing up the testing, as the "dead" woofer was showing as dead on the meter too.

With the radio playing I was getting a ca. 12.xx mA signal from the feed wires to the tweeters and woofers on both front doors; nothing from either mid-speaker feed.

Not especially surprising in light of the next checks, continuity. Both front doors have full continuity from the loom ISO plug to the woofer and tweeters - positive and negative. Both doors have continuity to the mid range speaker on the positive, not on the negative. I shouldn't but I think it's fair to assume that I'd find the same on the back doors if I could be bothered to remove the door cards again.

So, an 'earth fault' somewhere?? Or with a 'mid range' install maybe the mid speakers were never supposed to work?? I'll have a look at the electrical pages in the WSM to see if I can make any sense of them, and maybe find where the earth issue or connection might be?

In other news I have ordered a set of the JBL component speakers so at least I'll have good woofers and tweeters. Maybe I'll be satisfied at that as far as sound is concerned - but I do always like things to work as they should so I'm interested in chasing down why the mid-range cabling doesn't have negative continuity.

Also, FWIW the car loom is simply two ISO connectors. There's an extra small/medium yellow multiplug on the loom too - just floating in my case - but I'll see if I can figure out what that's supposed to be too. (UK X plate vehicle - 2000my)

If your car is a base model, it wouldn't have had mid range speakers originally, just the main bass speakers and tweeters. So it sounds as though the door cards have been changed at some point with ones from a higher spec car with the mid range speakers although the wiring isn't there for them. If you look at the diagram for the mid line system (ETM section E6, page 6-7). You'll see that all 3 speakers in the front doors and both in the rear (no tweeters in the rears), are wired in parallel. However, the negative side (the wire with the black stripe) has a 2.2uF capacitor in it to block the low frequencies to prevent distortion but this will also block DC voltages so your meter will show it as open circuit. Although the tweeter should also have a capacitor in it so you shouldn't see continuity. The capacitor is normally attached to the back of the tweeter. The capacitor in the mid range feed will be a 'lump' in the wire covered in heat shrink. Check the wiring back to make sure it is connected to the other speakers. If it had an aftermarket head unit in it when you got it, chances are somebody has been playing with the wiring.

If the DIN plugs at the radio head end are both 8 way, then your car never had a sub woofer as that would mean one of them would be 10 way. With 8 way on both (power and speaker outputs) they will plug straight into a head unit with standard DIN connections.

Thanks very much for that. I haven't managed to open the electrical manual yet, so the references will be handy.

I think mine was maybe a base model, with various options ticked. I suspect it was initially bought as a company car back in the day, so maybe minimising purchase price to minimise tax??

Anyway, I'm fairly confident the door cards I've just taken off are original, and there's what looks very much like factory wiring to all the mid speakers. I could send pics (where are we hosting pics now that Imgur has stopped working?) but I don't think it's really worth it - just a pic of the standard door wiring.

If I'm understanding you correctly though, for the mid speaker wire, an open circuit/lack of continuity doesn't mean anything's wrong just that the capacitors are 'blocking' the tester? This then leads me to think that the wiring to the mids is OK - assuming they are connected. I could accept that one door might have a break or a fault, but to have that happen to all four seems unlikely.

My next step is to look at the door wiring - unwrapping the loom to see if I can find where the speaker wires in the door join the main loom. If there's something obvious there, fair enough, if not I was planning on taking my feed for the JBL crossover directly from the main incoming wiring pair, and ignoring the mid speakers.

Thanks again.

A capacitor will pass AC but block DC, so the audio will pass through it but not a DC voltage from your meter. The value of the capacitor means it blocks low frequency AC so only the higher frequencies pass through to the speaker. Trace the wires back from the working, bass, speakers and you should find the additional wires that go to the mid and tweeters. The standard tweeters have 3 terminals, one goes to one side of the coil, the other side of the coil has the capacitor connected to it and the wires go to the one side of the coil and the capacitor.

If you fit crossovers, you don't need the capacitors as they form a crude crossover so can be removed (or bypassed). If you fit 2 way crossovers, feed the bass speaker from the low frequency output and the mid and tweeter in parallel from the high frequency output. If you use 3 way crossovers, then you have an output for each speaker.

Thanks Gd.
The new speakers have arrived but I won't get near them until next week now. I appreciate the comment about supplying the mid and tweeters from the same output on the crossover though. I wouldn't have thought of that, or with my limited knowledge of electronics, would have been paranoid about doing some damage. I had kind of reconciled myself to having two speakers in the front doors (tweeter and bass) and just forgetting the mids. This means I should get all three going. I'll update when I've done the job. Ta.

I fitted an aftermarket Kenwood unit to my spare P38 that originally had the door amps (high line system). The door amps incorporate a crossover so they feed bass from one output and the mid and tweeter from the other. I removed the door amps and replaced them with cheap 2 way crossovers and wired them exactly as they had been before, bass from low frequency output and mid and tweeter from high frequency output.

Step daughter used it to go to work as her Aygo needed some work and said that while a P38 felt rather large for her (5' 5" and 8 stone), she wished she had the same sound system in her car......

Well, only 6 years after starting this thread I reckon I can tick this job off the list... all the black/AshGrey door cards fitted, and (almost) all the speakers working. Delighted. All I need now is an MOT so I can get out and enjoy it!

I initially decided to use the 'mid speaker' wiring as the feed for the crossover, after removing the capacitor. Before going any further though, having removed the capacitor, I reconnected the mid speaker and got a good volume so I was happy to proceed.

However, once I'd done the wiring (as above) with the tweeter and the mid on the same crossover output, and tested it all, I was getting next to nothing from the mid speaker. I guess this makes sense if it was only getting the tweeter signal.

I slept on that, after having done one door, and then decided to rewire it using the bass / woofer wiring as the feed to the crossover. The crossover now only supplies the woofer and the new tweeters; and I re-connected the mid speaker to it's original wiring (minus the capacitor). All good. Decent output from 8 out of 10 speakers, and I'm really pleased with the sound - though I'm no audiophile. Quite pleased with the neat-ness of the install too, fitting the crossovers in the space where the door amps go.

As I'd done the rear doors before learning about the capacitor in the mid-speaker wiring, those two speakers are still being fed via the capacitors and aren't doing much. So one tiny thing to do yet, once I can find the enthusiasm or the need to remove the 2nd row doorcards again, would be to remove those capacitors from the mid speaker supply - but I can't call that any kind of priority. It makes me wonder whether the factory headunit, even one using the ISO plugs, was sending out a 'chunkier' signal to the door speakers, necessitating the capacitor on the mid speaker wiring, but still allowing enough to get through to generate some output?

Anyhow I'm happy, and grateful for all the advice that's helped me get this far. Ta.

Feeding the crossover with the full range output from the head unit, is the correct way to do it. The low frequency, bass, output will have components that block higher frequencies while the high frequency output will be blocking the low frequencies. As you now have crossovers, that will be blocking the low frequencies in the feed to the mid and tweeters, so you don't need the capacitors.

As your car never had door amps or crossovers, LR went for the cheap option of using capacitors. Without them, so all speakers are fed with a full range signal, in audiophile speak, the sound would be 'muddy'. If you think about how a speaker works and why there are 3 in the front doors, the reason for the capacitor, or a crossover, becomes more obvious. The main output is varying frequencies but if a full frequency signal is sent to the mid range speaker, the low frequencies will move the cone a larger distance than the higher frequencies, meaning that the mid range frequencies disappear as the cone can't be moving a short distance for the higher frequencies at the same time as it is moving a longer distance for the lower frequencies (but due to the small size, it can't give much bass anyway). So the capacitor blocks the low frequencies so it can concentrate on the higher frequencies. With the capacitor removed, you'll get more volume but it will be trying to output the low frequencies but it doesn't need to, as that is what the bass speaker is doing. Depending on what you are listening to, the mid range (mostly vocals) will be at a lower level most of the time.

Basically, by using crossovers fed with the main full range signal and wiring the mid and tweeters in parallel, as you have done, is the correct way of doing it. Just make sure you have them wired + to +......