Alternator/Battery Prob

The message from Simon Dean contains these words:

Listen carefully to each speaker in turn (fiddle with the fade/balance) and see whether it's a particular speaker. They sometimes fail as they warm up, ones in doors and tailgates being more vulnerable 'cos they've been slammed about.

Thanks for the reply.

Bizarrely enough, I tried this experiement yesterday... I found a track that was causing a blip at exactly the same place. Being confident I could recreate the problem 10 times in a row, I shifted the fader to the rear. Sound was fine. Shifted the fader to the front, sound was fine. Shifted the fader back to normal, still fine!!!!

Maybe I can try shifting the fader frontwards first next time.

I am using JBL's in the front and rear, so they should be OK?

Never had the problem with the old Clarion nissan branded head unit and it seems I played that even louder!

Cya Simon

The message from Simon Dean contains these words:

No idea - I know sod all about car radios except faults mine have previously shown.

For example, I know that the secondary of a big mains transformer in the power feed takes all the noise from a whiney alternator out nicely.

That's 'cos it's working as a choke, and hence acts as a high resistance to high frequency interference. Most modern units have an inline choke in the power feed anyway.

As regards the original clipping query, sounds to me like a thermal problem with something in the head unit. Could be faulty semiconductors, but it could just be a dry joint which is affecting some component when it gets warm - I had exactly this fault on a Kenwood which was under warranty; it just went off after 45 minutes (which was a pain for diagnosis as I don't often drive further than 45 minutes!). Took it back to the shop; they soldered it up and it has been fine ever since.

I would agree, sounds like a duff regulator in the Clarion which starts to give a lower voltage as it warms up.

Dave

The message from Chris Bolus contains these words:

That'd be why I fitted it!

Seems fairly obvious the fault is in the head unit if it wasn't there with your previous unit. You should be able to get it sorted under warranty.

John

Balls... I bought the smegger off eBay. From Germany. Wonder if I can get a straight swap from Clarion UK?

Teach me to save £50.

Cya Simon

Mind you the old unit was the original 12 year old Nissan jobby... and I was hoping you weren't going to say sorted under warranty... I bought it on eBay from Germany. A new unit it is... But I don't fancy sending it back to Germany.

Cya Simon

Well, that's the problem with Ebay, isn't it. The fact that using the fader can affect the problem indicates a faulty unit. If it were just bad suppression the noise would be there all the time.

John

I've just spoken with Clarion, they're trying to find more information for me... First they thought that maybe the unit wasn't getting enough power, but with the voltmeter, I can confirm that it gets 13v while driving around, and even sitting with the radio on the passenger seat with enough cooling, its getting 10v, but sounding fine.

It's only in the dash that it's going wrong.

So it seems definite the problem is overheating, but they don't so much think its a design or manufacturing fault, so nothing I can do, apart from "get an external amplifier".

Question is, why is it getting so hot? Any ideas whether I should be checking the wiring, or possibly trying not to let the radio ground itself through it's chassis on the dash? unfortunately I don't have any other options for that approach, since that's how the Nissan Wiring Loom was designed, without a ground wire, it has to ground either through the aerial, or through the radio chassis. Wondering if that might affect it?

Cya Simon

But it _will_ get hot, and it's designed to. But it looks as though there is an internal fault which is triggered by the heat - think of it this way. A "dry joint" is one where the solder hasn't flowed properly over the components, or perhaps has fractured later due to mechanical stress. While it's cold (in this case), it makes sufficient contact to work properly. When it gets hot, the thermal expansion opens the gap such that it no longer works properly.

Get the fault repaired. Clarion may consider doing this through one of their UK agents if you're lucky - try them.

From the email, it appears that they don't believe it was design to accomodate the confined space and heat of a Nissan Primera 1994, though I dont buy it,its a fairly modern car, and as such, most modern cars will suffer from a cramped space with little airflow. Someone said they'd look into it more deeply for me.

Thanks for the pointers though everyone. I'll use this all in the fight!

Cheers Simon

I have a 92 Primera and I have installed a Clarion DB348RMP CD/MP3 unit and there is more room in the Primera dash than a lot of other cars I have had and it works fine even with the heater on full blast it does not overheat or show up any of the problems you have stated. Trevor Smith

Ooh great, that's what I need, someone with the same car, and similar radio... Thanks very much for your reply!

How high on average, would you say you have your volume knob? And what about gain controls?

How do you ground the radio? Have you rigged up something from the black wire from the radio, or do you use the metal chassis of the radio like a stock nissan radio?

Cheers Simon

I rely on the mounting brackets to give me the earth as I expect that as on most radios the wired earth conection is attached to the radio chassis and circuit board inside. The most i can have the volume is 25 as I am just using the standard nissan speakers at the moment and thats about all they can handle. Hope thats of some use. Trevor Smith

Thanks for the reply Trevor. Very handy to know.

I've upgraded my speakers to JBL's all round, not bad, bass is less than it was, but clarity has greatly improved. But I can't push the thing much past volume 25 without after a while everything going wrong and clipping being induced.

How easy was it for you to get the Aerial Adapter too? Mine had a Nissan Diversity... Took many months of searching to find I believe the PC5-87 adapter from Halfords. Just over £8, compared to some of the local smaller audio shops wanting £24.99!

I'll pass on these thoughts however to Clarion, and hopefully maybe get someone to take a look at the radio under warranty.

I was thinking of getting an Amplifier at some stage, when I eventually get round to upgrading the speaker system even further and add a subwoofer, to trawl the streets playing "Puff the Magic Dragon" - no joke, that really is an ambition of mine.

But I didn't want to upgrade just yet, I can't afford it!

Cheers Simon