[i30joe]

While the car isn't running the AM radio is as clear as day but as soon as you start the ignition the radio suffers badly with interference is this a known problem. Any known fixes?

[asathorny]

Based upon 60 year old knowledge, when all  cars caused interference, it sounds like the supressors goosed.

I remind you tho, that this is based on 60yr old knowledge   

[Surferdude]

I've had the same problem,  getting progressively worse, for years.

[ibrokeit]

I recall some people mentioning this could be a grounding/contact issue - though I don't remember where.   Could be as simple as removing and reinserting the plugs into the head-unit (once you have got to them that is).

[Phil №❶]

It's usually a loose plug in the head unit, however, there is the possibility of a bad connection in the plug itself. Basically, check all power leads and aerial at the rear of the head unit. failing that, look at the other end of the aerial for a poor connection too.

@Asa , not too much suppression required in a Diesel engine. 

[Surferdude]

It's usually a loose plug in the head unit, however, there is the possibility of a bad connection in the plug itself. Basically, check all power leads and aerial at the rear of the head unit. failing that, look at the other end of the aerial for a poor connection too.

@Asa , not too much suppression required in a Diesel engine. 

But my problem is identical.  And mine is petrol.

[Phil №❶]

Which is why I say it is not a suppression issue. If the signal is weak and or, the shielding in the cable or centre electrode is damaged, then you will get interference. Your car being petrol, has the added complication of multiple high voltage emissions which do have to be suppressed. Generally, suppression is achieved by using silicon spark plug leads (which I don't like at all) and of course, some alternator suppression as well.

[Doggie 1]

I think it is a suppression issue.
If my car is turned off it is acceptable.
When I turn the car on, it depends how many accessories are operating at the time.
The NavMan GPS, the mobile phone charger and the DOD dashcam each reduce the quality of AM radio received.
I have posted about this before and don't know why a good auto electrician wouldn't be able to sort this problem, but two and a half years in, I still have it.   

[Phil №❶]

If you were in my neighborhood, I'd make a test aerial cable and try it.

I am able to listen to Leigh Creek 555 kms ABC 639 KHz, Renmark, Murray Bridge & Dry Creek with static, only because of distance.

[Doggie 1]

Thanks Phil.
I live some 90 kms south of Perth and prefer AM radio (if I listen to music, I'll choose my own) as I like to listen to current affairs/politics, etc.
There is lots of interference from all the gadgets.

[Surferdude]

I don't have any of those gadgets.
Engine off reception is excellent. Even Sydney AM stations at night.
I'm sure it's easily resolved but like Dave, I just don't get around to calling on a sparkie.

[i30joe]

Thanks for all the ideas and possibilities as my car is still just in warranty I think I might just take it to them and let them fiddle about with it I have a few little issues I want looked at anyway.

[Raid]

Thanks for all the ideas and possibilities as my car is still just in warranty I think I might just take it to them and let them fiddle about with it I have a few little issues I want looked at anyway.

That happened to me once and if I'm playing CD when I turn the car off and on it won't go back to CD it will just go onto Am with a lot of noise but it sorted itself out don't know how tho.

[ibrokeit]

I think it is a suppression issue.
If my car is turned off it is acceptable.
When I turn the car on, it depends how many accessories are operating at the time.
The NavMan GPS, the mobile phone charger and the DOD dashcam each reduce the quality of AM radio received.
I have posted about this before and don't know why a good auto electrician wouldn't be able to sort this problem, but two and a half years in, I still have it.   

Ahh - I see.  The gadgets are probably emitting some RF interference - unfortunately AM can be susceptible.  the questions are... a) where from? and b) can anything be done?

If the interference is being emitted along the power wires - then clamp-on or toroidal inductors *MAY* help (or there might not be any effect at all).  Clamp-on can look better, but are more expensive. Toroidal are cheaper but you have to be able to pass one end, or other, of the wire through the centre and it shortens the overall length of the wire.   I would suggest try a toroidal first - to see if it has any effect - you may want to loop the wire around twice.

Can't really give any advice on which one to select permeability wise (e.g. L8 vs L15 - U maybe used in place of L), and if it will have any affect at all, but I would give L8 and L15 a shot - the toroids are cheap enough.

You can get toroids in packs of 2 or 4 for about $3 - $6 - see Jaycar Electronics

[Doggie 1]

 

[ibrokeit]

You're welcome.  Of course a couple of things to note...

My suggestion above is on the basis the RF noise is being transmitted along the power wires into the effected device - otherwise radio grounding (and shielding) should apply.

Some might be harder than others to try this on - such as the phone charger... if is fairly std. plug with charging wire (i.e. the regulator/electronics are in the plug) which fits directly in the 'auxiliary power'/'cigarette lighter' socket then trying it on it will be 'fun'.   Basically you would need to apply it to the wiring to the socket inside the dashboard - although for finding out if it would have an effect you might get away with a short appropriate 'extension' lead.

The downside to RF noise, and trying to suppress it, is that moving things (such as to test something) can effect the problem trying to be fixed - though more so when the issue is being transmitted over air (taking us back to radio grounding and shielding) rather than by wire.

If the devices are emitting noise, but not by their power supply wires, but rather out their cases - then trying to suppress it gets harder (there are sprays you can get to coat the inside of cases, etc. - but then you have to open cases, make sure the coating doesn't cause a short, etc.).

HOWEVER if it is coming out their cases (within the legal emission limits) then the radio (and antenna) grounding (and RF shielding) should be taking care of it - which takes us back to bad grounding/shielding of the radio itself.

[Phil №❶]

Given that it appears to be an isolated case, I'd be leaning towards grounding / shielding, otherwise everyone's equipment would be just as noisy IMO.

[Surferdude]

Given that it appears to be an isolated case, I'd be leaning towards grounding / shielding, otherwise everyone's equipment would be just as noisy IMO.

I wonder how many actually suffer from it as most people seem to have moved on from AM radio.

[Doggie 1]

Given that it appears to be an isolated case, I'd be leaning towards grounding / shielding, otherwise everyone's equipment would be just as noisy IMO.

I wonder how many actually suffer from it as most people seem to have moved on from AM radio.

Current affairs are on AM.

[Surferdude]

Given that it appears to be an isolated case, I'd be leaning towards grounding / shielding, otherwise everyone's equipment would be just as noisy IMO.

I wonder how many actually suffer from it as most people seem to have moved on from AM radio.

Current affairs are on AM.

I prefer the music but you and I and maybe one or two others are about all who use it.

[ibrokeit]

Given that it appears to be an isolated case, I'd be leaning towards grounding / shielding, otherwise everyone's equipment would be just as noisy IMO.

Or it could just be Doggie 1's equipment.   Not that I am saying anything about his equipment mind you 

[Doggie 1]

Given that it appears to be an isolated case, I'd be leaning towards grounding / shielding, otherwise everyone's equipment would be just as noisy IMO.

Or it could just be Doggie 1's equipment.   Not that I am saying anything about his equipment mind you 

Probably more that I live 90 kms from the CBD, which is further than most AM radio users.

[Sydney Lady]

Did anyone manage to fix this problem. AM is my preferred band but I have to use FM as the AM reception is too bad.

[Phil №❶]

You have very strong AM radio in Sydney, so if there's a problem, get it checked at the dealer, or a reputable car audio installer.

[Doggie 1]

No, I still go without much of the time, living where I do.   

[Dazzler]

No, I still go without much of the time, living where I do.   

Yeah, at your age I can understand that.. but what about  the radio?

[Phil №❶]

Me too