MW Interference, Alternator? Ground? Something else?

[Skezza]

Hey guys,

As a follow on from my topic a week or so ago, I fitted my new stereo (With varying degrees of success, failure and swearing... ill eventually write a thread about it to help other people. It's better when it's written by a complete muppet because all bases regardless of how insane are usually covered lol!). It now works great, sounds great, and kind of looks pretty neat too. A bit chavvy of course but then again most aftermarket CD players seem to have this boy racer look. It must be a marketing thing because even the top of the range Pioneers, JVCs and Alpines tend to be styled on Blackpool lights rather than casual classiness.

Anyway, opinionated bile aside, the radio is working and all that, but I've noticed a problem with MW. It's incredibly distorted when the engine is switched on. As in only when the engine is switched on. Engine off. It's fine, sounds quite good for MW in fact.

The OEM one was definitely distorted when the engine was on, but not so badly. I'd say it was at least listenable, if you could deal with a little bit of hiss which sometimes came, went very bad and went. Trust me I got fairly used to it. However this radio, the hiss is unbearable when the engine is on. As in, it's just like a TV with static and nothing else. I'd say you would be lucky to actually understand anything, a single word would be impressive to be honest.

What do you guys think? I googled it and as with anything car related, it's very fragmented. No real solutions, lots of speculation, lots of bad suggestions ("chop your unused RCA connectors off and tape the wire ends. This will stop the..." blah blah, mate you're talking ****ing bull****)

Halfrauds are selling an alternator interference suppressor for 4 quid :

http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_189944_langId_-1_categoryId_265890

I know it's just a capacitor but would fitting it help? Would fitting it be easy? Any tips for a complete newb :)

[Skezza]

Also, would a new aerial help ? The old one isn't in great condition. Or is interference only when the engine is on not really related to the aerial?

They're cheap enough on eBay tbf.

[marvelt]

I'm pretty sure this is a common vw thing,

you can get an adapter/ plug from any good radio dealer that should sort it out.

[Skezza]

hey marvelt, thanks for the response. I went into Halfrauds and grabbed the alternator interference suppressor as I displayed above. The two kids in their knew even less than me, which is scary considering they work in a freaking car shop, I mean, I know **** all. The guy there suggested a radio interference suppressor which is a large box which behind the radio itself. To be honest, I cant imagine there is much chance of fitting the large box so I bought the little suppressor that's connected directly to the alternator. Is there anything else I should be looking for? Video is uploading to youtube, will be live here:

Sack the video for the moment, will upload it later, internets playing up lol!

In all honesty, I don't think it truly demonstrates the difference. Honestly, with the engine off, it's very clear, with the engine on, its so hissy its untrue.

Any further help or fitting suggestions would be great.

Edited May 14, 2012 by Skezza

[marvelt]

i was fitting an aftermarket head unit into an arosa and needed the adapter for the wiring as the original had been lost, so went into a radio/car electrics shop to get one and whilst in there he explained about mw interference on vas and tried to sell me a small wire with a plug on it etc, that you connect up to the back of the head unit somewhere and it cuts out the interference .

my suggestion would be to try and find a local specialist and see if you can get your hands on one.

[Skezza]

Hey thanks for your response. Ill pop into town at the weekend and see what they say. I'm very pushed for space behind the head unit so any adapter would have to be tiny or alternator mounted really.

[Skezza]

OK, an update...

I fitted a brand new aerial.

It's made a huge difference. The audio quality is actually listenable now, but there is still some popping going on. Now, of course, it might be the head unit, but what do you suggest?

The popping goes up, as the car gets faster and goes down as it gets slower to a stop. Note, that its NOT a whine, it's specifically popping.

[Skezza]

Okay, a further update, talk about chasing shadows lol.

The noise definitely gets louder when going faster and I have noticed in some instances a slight whine. So I think the next step is to fit the suppressor.

Is it possible that this is being caused by the head unit? Like, when the car is off, the quality is fine, excellent in fact. No crackles or anything. But don't get me wrong, it's not a Pioneer or Alpine, so could it be the head unit isn't quite up to it?

I've also noticed that going through certain places the crackling clears up. Like, I was going through a bit of countryside and the crackling almost disappeared entirely. None whatsoever. Which made me think its a **** head unit, but the thing is, the head unit is fine, excellent quality when the engine is off.

I guess the alternator interference suppressor is the last roll of the dice.

Dear me. I tell you, it's tough being a complete novice

Edited May 22, 2012 by Skezza