dave3d wrote:

I am also one of the bodgers. It is a design fault that an inspection hatch was not included (as it was for other L/R models) ... also a level sensor on the coolant expansion tank. I keep meaning to fabricate a proper surround with a bolted down cover. Mine is just taped up and I agree is a bodge at the moment. Dropping the tank is easy if you have it on a car lift.

As I said, if you do it yourself then it's your car and your choice but if you pay someone to do a job and they do something like that without telling you they've done it, that's just not on. I've dropped a tank a couple of times with the car on axle stands and lowered it down with a plank of wood on a trolley jack but I agree it isn't really that much fun.

Mazz, this place was intended as a sort of virtual pub anyway so it is much like a bunch of mates, some more local than others though. Like most cars (and things) there are common problems that crop up every so often so we will all have experienced it before. In 9 years and almost 180,000 miles I've experienced everything that can fail at some point but mine is petrol so I'll have different faults than you with a diesel.

Diesels aren't my forte even though I do maintain one for the the owner, a woman who lives just outside Paris. There's a few fairly common things that will cause your symptoms though. I'm a little concerned when you mention the fuel pump under the back seat as the fuel pump is in the fuel tank. To get to it you drop the tank although some bodgers think it easier to butcher the car and cut a hole in the floor. If you are doing it yourself that's one thing but if you are paying someone to do a job and they bodge it I'd be inclined to ask for my money back.

The battery drain problems are well known but unfortunately many mechanics don't even understand electrics (it doesn't go up and down or round and round and you can't see it) so expecting them to understand RF is like expecting them to understand brain surgery. I'm coming up to retirement after 47 years of working in RF and it is a black art to most people so much of the stuff you read online is rubbish, it's a case of filtering out the rubbish from the facts. For instance, broadband or Wi-fi won't affect a P38, neither will cordless phones, mobile phone masts and most of the other things that get the blame.

By now you should have realised that you should have taken Marty up on his offer, but I can appreciate you not wanting to trust someone you didn't know. Anyone on here will be able to at least tell you what the problem is, if not fix it, as there aren't many things we've not come across before. One question you haven't answered is what engine, petrol or diesel, as that makes the probable cause different.

One thing I discovered last night (or very early this morning to be precise) is that the brush guides on the Valeo motors are a hard plastic. If the brushes aren't making good contact they get hot and that allows the plastic guide to form a ridge so the brushes are no longer touching the commutator. I got the brushes out of a noisy P38 blower motor and found they were no better than the ones in the Merc motor I had in bits. Managed to clean up the guides, sand the original brushes down and it now works perfectly.

However, in James's case, I suspect it is the speed controller that has died rather than the motor.

Check by seeing which one isn't moving before pulling it out. Having just taken one apart to see if I could nick the brushes to go in a very similar Valeo blower in t'other half's Merc, you'll be very lucky getting it apart. It can be done but.......

You are right, I am confused, relay 6 controls the RH blower so if it behaves itself with that out, then it is that one at fault. Blame it on the heat, we aren't used to it being hot two days in a row in the UK.

Normally the outer electrode gets very thin and there's a gap you could drive a bus through. I think you gapped yours down when fitting them, maybe that has made the difference?

But you don't need a huge one and a four stage smart charger will do a much better job than a solar panel. I bought one of the Lidl copy of a Ctek for just over a tenner which I connected up to trickle charge a battery. Worked fine for a while but then decided it was going to run flat out all the time, toasted the battery and got so hot the plastic casing melted. So I'd be very wary of leaving one of them connected permanently.

It depends what you mean by un-amped as there already is an amp in the head unit. In your case, it is rated at 4x45W, so that is the 4 channels each with a 45W amp to drive the speakers. An amp will be rated at an output figure into a specific impedance load, so you will see something like 45W into 4 Ohms, but it could equally be rated at 60W or 80W into 2 Ohms (and some are to make them sound more powerful than they really are) so as soon as you add additional speakers you are reducing the impedance and hence the amount of power it can supply (until you are down to a virtual short circuit and it either burns out or shuts off to protect itself). So yes, there is a point where adding more speakers won't increase the amount of sound as there isn't enough power to share between them but you are very unlikely to reach that point unless you get really silly and install speakers everywhere. Hence the need for huge 10,000W+ amps to drive the large amount of speakers at a concert, you've got to have enough speakers to be able to shift enough air to make the sound audible (at eardrum splitting volume) over a large area.

I've no idea what the output of the DSP amp is, or the door amps for that matter, but I suspect they will also be rated at something like 50W per channel (or in the case of the door amps, per amp). That would allow a manufacturer to say that it has a 250W audio system if you add the sub amp in too. The L405 can be had with a 1500W audio system but you have to bear in mind that once up to around 60% of the rated output, you start to get distortion so to keep the sound quality good you need an amp that is only ticking over at normal volume levels.

Unfortunately, the ICE and Hi-Fi world is full of bullsh*t.

Running on LPG needs a better spark than on petrol and plugs seem to not last as long either. That's why I change mine every 10,000. For me that's £32 a year so no big deal. Yours won't take the BPR6ES plugs as it needs the others with the smaller hex, but as the actual electrodes are the same, I would think the same would apply.

A nice simple one. Plugs are so cheap, my local factors charge £1.99 each for BPR6ES so at £16 a time, there's no reason not to do them regularly.

I've got a very elderly boost charger. It was originally used to charge the batteries used to power old valve based Pye Westminster two way radios that were installed in all mail trains after the great train robbery. My predecessors at work would meet the mail train, provide it with fully charged batteries every evening and swap them for the ones that had been there since the previous day and get them charged ready for the next day. I sort of inherited it..... According to the meter on the front, it's capable of charging at up to 30A but I tend to keep it down below 5A so I don't cook anything and have never had a problem even on a P38. If I crank it up, it'll get a battery from flat to capable of starting the car in half an hour but I only do that if the battery is disconnected though.

It's obviously been affected by the missing pixels fault so it's there but doesn't show up.....

No, the blowers aren't visible through the pollen filter hole if the recirculate flaps are closed.

I've changed a VC on a late Classic with the same transfer case as on a P38 with it on a ramp. Fairly straightforward, no puller needed (on the one we were changing or the old P38 one we were stealing the VC out of) the hardest part was cracking the seal made by the RTV. RAVE says to rotate the cover but we found it needed a couple of whacks with a mallet to twist it and off it came. Although we had access to a ramp so used it, I wouldn't worry about doing the same job on the floor.

Relay 6 controls the Right blower motor, passenger side in your case, so it is the Left hand one that has died. Simple enough to confirm if you pull the pollen filters out you can see the blowers down the hole and see which one is moving and which one isn't. With only one blower working you will get much less air, less than half, because normally both blowers are shoving air towards the heater box and it has nowhere else to go other than through it. With one blower not working, some air will go though the heater box while the rest will just go out via the non-working blower. If you poke the recirculation button, that will close flaps between the pollen filters and the blowers and at least keep the air in the car.

You've got the opposite to what I had at the weekend. One blower stopped (due to a dead spot on the commutator), the Hevac detected the fault so cut the power to both blowers. Not fun on the first decently hot day we've had this year. Fortunately, I had a couple of spare blowers kicking around so changed the dodgy one and all back to normal.

RutlandRover wrote:

Would using one channel to power three speakers not reduce the amount of power each speaker gets meaning you lose overall volume and/or quality from each speaker? IE: if you split a 45w (the power my Android headunit claims to output per channel, unsure if that's peak or RMS) channel to three speakers wouldn't you then only have 3x 15w speakers? This is the assumption I made that led me to wanting power to each of the speakers.

No, because you are spreading the power between the speakers so the amount of air they can shift will actually be greater than having one speaker, giving more volume not less. The output of the amp is the full range of frequencies but the largest speaker can't move fast enough to reproduce the higher frequencies so they get lost. Equally the tweeter only has a 1" cone so works beautifully with the high frequencies but can't cope with the bass. The midrange then deals with the bits in between. Now you can just rely on the fact that the speakers won't respond to frequencies they can't really handle but it can muddy the sound as they will still try to, so the high frequencies will damp the cone in the bass speaker. This is where a crossover comes in. It is a set of filters so you feed it with the full range and it splits it into the three ranges, bass, mid and high which are then fed to the individual speakers. The non DSP mid line system (fed directly from the head unit) uses capacitors in series with the midrange and tweeters to block the bass frequencies while the high line system with the separate door amps uses a single amp but with a built in crossover so the bass is fed to the bass speaker and the rest is fed to the midrange and tweeter with a capacitor in series with the tweeter to keep the lower frequencies out. So what you have is 4 amps, one for each channel (FL, FR, RL and RR) with inbuilt filters to split the output between the different speakers.

The DSP system does much the same only it is controlled by a data line (so while it is only fed with a 2 channel stereo input, the data tells it how much to send to the front and how much to send to the rear) and can also alter the sound to give different effects by putting minute delays in outputs to make the soundstage move and add preset equaliser settings.

For the sub you just have one further amp, sometimes mono to drive a single speaker, other times stereo to drive a pair (or a stereo input that is then combined to drive one speaker). Looking at example 2.2 that Clive linked to, they are using the original head unit, passing it through an attenuator, which may also convert between balanced and unbalanced signals. Unbalanced means one leg is grounded, so a 1V peak to peak signal would be between 0V and 1V, whereas the same 1V balanced signal would vary between -0.5V and +0.5V. From that they then feed a 6 way amp, almost certainly incorporating filters, to drive the 4 main channels and a stereo sub. Virtually identical to what Marty's 4 door amps substitute for the DSP amp solution does only it doesn't include the sub amp as that was separate in the first place. It'll work fine as a substitute for a dead DSP amp and retaining the original head unit but when you start feeding it with signals it wasn't intended to be fed with, then you are in uncharted territory.

I suspect the reason for your whine, although not the pops and crackles which as you say are down to your soldering skills, is because the outputs from your Android unit are unbalanced but the amps are expecting to see a balanced input. Careful experimentation with grounding is needed to sort that and possibly also some filtering on the supplies (I've got a few boxes of FX1588 ferrite cores if anyone can use them or even knows what they are...).

However, Chris still hasn't popped up and told us what he is trying to achieve......

RutlandRover wrote:

You'd need something to power each of the speakers. No headunit will have enough outputs to power as many speakers as these cars has. Most headunits have 4 speaker outputs at most. FR, FL, RR and RL.

That, along with a sub output, is all you need. The DSP feeds the bass speaker on a separate feed to the mid range and tweeter but you could just parallel them up or run via a 2 or 3 way external crossover. So the FR output would be connected to all 3 speakers in the FR door. I suspect the DSP amp has the crossover built in so rather than it having 8 outputs, it still only has 4 but with the front feeds going via an internal crossover and giving a bass output and a mid/tweeter output from the same input. Having 3 separate speakers is no different, in fact preferable, to having a 3 way component speaker. Most cars these days run 3 speakers per channel so any head unit should be capable of powering them.

What we don't know is what you are trying to achieve (other than having window rattling bass). I know you've got the Android unit installed but you've retained your original Alpine head unit. Are you planning on retaining that or are you going to change that too?

Lpgc wrote:

While on the subject of cleaning plastic lights... Not that I have any need for this at the moment but has anyone ever tried similar with glass headlights or even windscreens? Not yellowed in the case of windscreens but the tiny marks and scratches they get over the years.

Jewellers Rouge and an awful lot of elbow grease......

If you've got the DSP amp, you haven't got the outstations (amps) in the doors, speakers in the doors are wired directly to the DSP amp. So you can run from the head unit to the speakers by linking the wires where the DSP amp used to be. The problem is that the DSP amp is only fed with L and R signals, no front and rear feeds. Marty will no doubt confirm but I'm not sure there is a pair of rear outputs from the head unit, my understanding of it is there is the L and R and then a data line so the output is split front/rear in the DSP amp depending on how you have told the head unit.to divide it.

If it's working why are you removing the DSP amp? I can't see there's anything to stop you simply replacing the existing sub amp and speaker with a different one.