[constipated]

I had the radio in my car replaced to fix multiple issues, including the crackling over bumps, the booming when cranking the engine and it also fixed the clock not being accurate.

Issue is that whenever the AM radio signal is slightly weaker, eg going under an overpass, being under an awning at the service station, under my carport, or in a tunnel, and the engine is running, I get a horrible high pitched interference sound which overwhelms the AM.

It there any way in which something plugged in the cigarette lighter outlet could interfere or damage the radio?

Is there any way that there could be an issue with the wiring in my car which is causing damage to the radio?

[Dazzler]

Sounds more like interference than damage to me.. sounds like something needs a suppressor on it 

[Phil №❶]

I would recommend disconnectning any extra devices in the cig lighter and see if that stops the interference. Try with the engine off and then on to see if it comes from the engine  / alternator.  It could just be that the station signal is not strong enough. A wiring fault that could damage the radio would normally blow a fuse. 

[Doggie 1]

Yes, when my phoner charger is plugged into the cigarette lighter I get a lot of interference noise through the radio.
I figured it was probably my phone charger to blame.

[constipated]

I would recommend disconnectning any extra devices in the cig lighter and see if that stops the interference. Try with the engine off and then on to see if it comes from the engine  / alternator.  It could just be that the station signal is not strong enough. A wiring fault that could damage the radio would normally blow a fuse. 

It definitely seems to only be present with the engine on.

The only thing is I don't remember this happening a few weeks ago.

It is happening without anything plugged into the cigarette lighter. The only reason I ask was the last time, the booming used to be louder with something plugged in. But I don't see how the 2 should be linked.

Later today I'll try and post a sound recording of it to illustrate.

[Phil №❶]

As you are driving a diesel, there are no high voltages present in your car eg coil, spark plugs etc, so my theory would be the alternator requires a suppressor (as Dazz suggested). These devices produce 110v AC internally which is rectified to DC volts for the battery. Is the noise constant or does it vary with engine revs.

[constipated]

For the experts here:

Sorry about the 3ga format from my phone. Should play on VLC media player.

Here is sample 1:

http://www.fileden.com/files/2012/3/16/3279030/Voice%20006.3ga

Basically it starts off with interference, get better reception midway and it goes, then drive under my carport and it comes back.

Sample 2:

http://www.fileden.com/files/2012/3/16/3279030/Voice%20007.3ga

Again under my carport with engine on. Then switch off the engine, and there is a high pitched whine after the engine is off which then fades away.

Anyone's expert diagnosis is welcome.

[Phil №❶]

I have listened to both examples. The noises do not sound like interference from the engine to me. Rather, it sounds like the radio is not tuned exactly to the station frequency. Perhaps retuning may help. There are other considerations I would mention though.

1. AM band is bad for picking up electromagnetic interference from power lines, engines etc, unfortunately, that is a characteristic of this type of radio wave.

2. In Australia, AM is transmitted from 540 KHz to 1600 KHz approx. The higher the frequency, the weaker the radio. Notice the ABC grab the best end of the AM band, the lower frequencies. This is because the lower frequencies are able to penetrate walls and obstacles better than high frequencies, which tend to be reflected rather than penetrate. That's why TV is hard to receive in a car.

3. Number 7 sounds like the station is being swamped by another more powerful signal, possibly from a closer transmitter. Number 6 sounds very much like shortwave scrambler interference which is an entirely different band altogether.

As the tuning in these radios is electronic and very accurate, (so FM stations can be tuned accurately), I can only suggest that if retuning doesn't help, then back to the dealer I'm afraid. I am not familiar with the tuning procedure becaule I've never need to but if you can tune a radio station manually, make sure you store the station's frequency exactly otherwise you will be storing it off station with the same results you currently have. I hope you can understand what I'm trying to say. 

[Dazzler]

I have to agree with Phil (i thought much the same thing) 

[Shambles]

I can't download the samples as our webfilter says the fileden site is p2p and possibly hosts porn

[Phil №❶]

Funny, I didn't have any probs. But then I couldn't care what it hosts. 

[constipated]

I can't download the samples as our webfilter says the fileden site is p2p and possibly hosts porn

Shambles try this:

Sample 1:

http://www.zshare.net/download/99405101d46ea47a/

Sample 2:

http://www.zshare.net/download/9940510339a4a4b9/

[Shambles]

Shambles try this:

Sample 1:

http://www.zshare.net/download/99405101d46ea47a/

Sample 2:

http://www.zshare.net/download/9940510339a4a4b9/

Nah, same thing. I'm behind HP's very strict blue coat webfilters

[constipated]

I have listened to both examples. The noises do not sound like interference from the engine to me. Rather, it sounds like the radio is not tuned exactly to the station frequency. Perhaps retuning may help. There are other considerations I would mention though.

1. AM band is bad for picking up electromagnetic interference from power lines, engines etc, unfortunately, that is a characteristic of this type of radio wave.

2. In Australia, AM is transmitted from 540 KHz to 1600 KHz approx. The higher the frequency, the weaker the radio. Notice the ABC grab the best end of the AM band, the lower frequencies. This is because the lower frequencies are able to penetrate walls and obstacles better than high frequencies, which tend to be reflected rather than penetrate. That's why TV is hard to receive in a car.

3. Number 7 sounds like the station is being swamped by another more powerful signal, possibly from a closer transmitter. Number 6 sounds very much like shortwave scrambler interference which is an entirely different band altogether.

As the tuning in these radios is electronic and very accurate, (so FM stations can be tuned accurately), I can only suggest that if retuning doesn't help, then back to the dealer I'm afraid. I am not familiar with the tuning procedure becaule I've never need to but if you can tune a radio station manually, make sure you store the station's frequency exactly otherwise you will be storing it off station with the same results you currently have. I hope you can understand what I'm trying to say. 

I do not fully understand what you mean about the tuning. It is set to the right frequency for the radio station. One step in either direction is 9kHz out and therefore the station is not tuned.

This interference comes on, like I said, only in reduced signal areas. I can understand in an underground tunnel, but when I have my car at the service station to fill up and it's under the awning, I don't expect that. The same is true for my car under my carport. These areas are still in the open air. Even passing momentarily under an overpass will bring it on for 1-2 seconds.

Could it be antenna problems, I don't know.

Also is the fact that it came on in the last week or so after I'd used a car charger. I don't remember it being like this 2 weeks ago.  I really don't understand what's going on.

[constipated]

Shambles try this:

Sample 1:

http://www.zshare.net/download/99405101d46ea47a/

Sample 2:

http://www.zshare.net/download/9940510339a4a4b9/

Nah, same thing. I'm behind HP's very strict blue coat webfilters

Maybe check it from home rather than work.

[Phil №❶]

Shambles,

Could you accept them as attachments in an email.

[Shambles]

Shambles,

Could you accept them as attachments in an email.

I'll wait until I get home, to a free and unfettered innernet

[2i30s]

Shambles try this:

Sample 1:

http://www.zshare.net/download/99405101d46ea47a/

Sample 2:

http://www.zshare.net/download/9940510339a4a4b9/

Nah, same thing. I'm behind HP's very strict blue coat webfilters

our site must be clean if your work filter isn't blocking it. 

[2i30s]

sometimes with an auto scan of the radio stations my radio will stop at a station,but stops 1 number off being exactly tuned in,i then need to give it a tweak manually. 

[constipated]

The interference is definitely something electrical within the car. 

It is intermittent. If it was alternator, would this come on and then go off during various parts of a road journey.

When the interference comes on, it causes high pitched whine. It seems to decrease markedly the AM reception. So when I go under an overpass or in a tunnel, the AM is completely overwhelmed so all you hear is high pitched interference.

I was wondering about other intermittent things eg radiator fan etc.

When I plug something into the cigarette lighter or into the USB port when the interference is present, you hear the high pitched noise wind up (ie it starts at lower frequency then increases, and the reverse when I pull it out).

What would alternator related interference sound like? Is it common? How does a suppressor work, and why would it not already be on my car? Is it troublesome to fit/replace?

[Surferdude]

^^^^^^^^^^

Looking forward to some feedback on this. I've noticed that if I'm on a staion which is a long way away, the signal has interference which goes away when I turn the motor off.
It's not overly bad and if the station is relatively close (50-100 klms the signal stremgth overrides the interference.

[Asterix]

If I remember correct, interference can occur if the ground cable for the radio is not well connected.

What would alternator related interference sound like? Is it common?

If the interference comes from the alternator, the noise will follow the revs of the engine.

[constipated]

Radio replaced. Fixed my temp display issue but interference on 873 KHz was there shortly after I drove off. I returned the car straight away but by then all the service people had already left for the day.

So not an internal radio issue it seems. It is perhaps less frequent now, not every day as before. I'll have to see how often it returns. Dealer says return to show them the interference during the day. Now I've just got to coordinate being near the dealership when it happens.

Any members with auto electrical knowledge who can diagnose based on the sound?

[constipated]

Brought the car back to the dealer to demonstrate the interference.  Met the foreman who seemed to recognise the problem.

End result will be another radio. He seemed to state that it seems to be a specific problem with the "noise suppressors" within the radio and 873 kHz which corresponds to one of the most popular AM stations in Sydney.

Apparently Hyundai are aware of this problem but unfortunately some of the radios which are meant to be fixed of this issue are coming back still with this issue, hence why a new radio did not fix it for me.

Have to cross my fingers for another radio without this issue.

In this instance the dealership was very helpful.

[Surferdude]

Brought the car back to the dealer to demonstrate the interference.  Met the foreman who seemed to recognise the problem.

End result will be another radio. He seemed to state that it seems to be a specific problem with the "noise suppressors" within the radio and 873 kHz which corresponds to one of the most popular AM stations in Sydney.

Apparently Hyundai are aware of this problem but unfortunately some of the radios which are meant to be fixed of this issue are coming back still with this issue, hence why a new radio did not fix it for me.

Have to cross my fingers for another radio without this issue.

In this instance the dealership was very helpful.

Might have to take mine in then. Very obvious at 882 kHz and only slightly less so on 693 kHz which are the two stations I prefer to listen to.

[constipated]

Might have to take mine in then. Very obvious at 882 kHz and only slightly less so on 693 kHz which are the two stations I prefer to listen to.

Hope it's the same issue.

For me adjacent stations at 954 and 702 have no trouble even when the interference is happening on 873 kHz. Worth a check.

[Keith]

Guys... I get this on 693Khz here in the UK in the Midlands, radio 5 Live for the UK members lol!

There is an alternative frequency for 5 Live for Northern folks, 909Khz... I get this crackle over eneven surfaces on that frequency too...

I can make it happen by hitting the dash with an open hand above the radio.

It doesnt happen on F.M, just A.M.

I took the radio out and gave the aerial connector a good clean with a proprietry Switch cleaner and it vanished for over a year... it's back now... so I need to do it again or find an alternative way of connecting aerial to radio.

Try it and see... its a no cost option and took me about 20 mins to do.

[Dazzler]

Gee you are very enterprising Keith (quite the back yard mechanic) 

[constipated]

Guys... I get this on 693Khz here in the UK in the Midlands, radio 5 Live for the UK members lol!

There is an alternative frequency for 5 Live for Northern folks, 909Khz... I get this crackle over eneven surfaces on that frequency too...

I can make it happen by hitting the dash with an open hand above the radio.

It doesnt happen on F.M, just A.M.

I took the radio out and gave the aerial connector a good clean with a proprietry Switch cleaner and it vanished for over a year... it's back now... so I need to do it again or find an alternative way of connecting aerial to radio.

Try it and see... its a no cost option and took me about 20 mins to do.

Ffoxy,

I think crackling is a different issue to mine. If you haven't had a listen, check out the sound samples earlier on for the interference.

Do you get that type of high pitched interference on 693 kHz?

[Shambles]

There is an alternative frequency for 5 Live for Northern folks, 909Khz... I get this crackle over eneven surfaces on that frequency too...

I can make it happen by hitting the dash with an open hand above the radio.

Yep. Same here while trying to listen to the cricket. Any bump at all, it's down the pan. Slapping the dash cures it for about a nanosecond in my case.

So I stick with FM and make do without 5L