Noise on my car radio. What could be the cause?

Question

Hello everyone...
Here's the deal. I have this mint original condition 1985 Ford Couuntry Squire wagon that I bought this spring, and I started hearing this noise in the original AM/FM Cassette radio from day one, but I just figured it was because that the original plug wires were old and needed changing. However, new wires, plugs and distributor cap have made no difference in the noise factor. It is obviously engine related, as the noise matches my RPM's. I hear it even when the cassette player is in operation, when it is on FM and of course loudest on AM radio selection.


So...what else can I change or look at to eliminate that aggravating noise?

Thank you.

Answer 1

they make a noise filter for the power wire on the radio.. any car stereo store

Answer 2

Found this on the web at http://www.msdignition.com/pdf/tech%20bulletins/tb_radio_noise.pdf#search='radio%20noise%20causes'
Radio noise can be broken down into two distinct categories;
Radio Frequency and Supply Line.
Radio Frequency noise is generated by the secondary side
of the ignition (coil wires, cap, rotor, spark plug wires). This
noise is radiated into the air and picked up by the antenna.
This noise will be noticeable on the AM band and will be
louder between stations. The FM band may also be affected
slightly. If you play a tape or CD, the noise will go away. Maintaining the secondary side of the ignition system is important
in eliminating radio frequency noise.
Supply Line noise is caused by varying loads of the
vehicle’s supply voltage. These variances are amplified
through the radio’s 12 volt supply wire and are heard through
the speakers. Supply line noise will be audible on AM and
FM as well as during tapes or CDs. For Supply Line noise,
the MSD Noise Capacitor, PN 8830, will help.
The Noise Capacitor will act like a filter on the heavy
power supply wires of the MSD. The MSD will draw its
power though the filter keeping all of the other accessories
separate which prevents supply line noise. A side benefit
is that the Capacitor will protect the MSD Ignition from
voltage spikes or current surges.

also found some more info here:
http://www.nrcdxas.org/articles/autonoise.html

If the noise is always present, even with the vehicle stationary and the engine off, then the source is either external or generated within the receiver itself. Generally, the latter is less likely, although not impossible. If the noise starts immediately after turning the key, but before starting the engine, the cause is likely somewhere in the electrical system, and often it's related to either electronic ignition or some sort of on-board computerized circuitry. If the noise starts when the engine does, then something which is activated by the engine is causing it.

Fortunately, the most common sources of vehicle radio noise are more obvious and easier to remedy. A static-like noise which is present only when the vehicle is moving, and which seems to be more of a problem at higher speed may be the result of a loose, improperly grounded or improperly mounted whip antenna. Check to make sure that the plastic insulator that separates the base of the antenna from the vehicle's body is present and intact. Make certain that the whip's mounting hardware is tight. Check the antenna cable, particularly where it connects to the antenna, and where it makes any significant bends or goes through any tight spaces to see if the ground braid is broken or damaged. In many cases, it is often easier to replace the entire cable unless it has been routed within body sections, in which case you may need to engage a specialist to replace it.

Another common cause of a static-like noise observed only while in motion is static electricity. This often results from the installation of new tires, and may persist for several thousand miles. One option to try to eliminate it is to rotate the tires, which occasionally works. In other cases, static electricity noise can be reduced or removed by means of replacement or added grounding of the receiver.

One additional note on this problem is that with the increase in the amount of fiberglass and other plastics used in the vehicle manufacturing process today, it is often more difficult to establish and maintain a good vehicle ground system. This also applies to the actual mounting of the radio itself, as the metal radio case must be physically grounded to the vehicle frame.

Often, it can be difficult to determine whether the noise is static electricity or a poor ground. One sure way to tell is to drive across an uneven surface. Static electricity noise will be interrupted by the bumps, whereas a ground problem will be enhanced by and timed with the bumps.

A noise which sounds like a combination of popping noises and static may be arising from the vehicle's sparkplugs. If the engine hasn't been tuned up I some time and/or if the sparkplugs are more than the recommended number of miles old, a full tune-up may solve the problem. In more stubborn cases, it may be useful to investigate noise-suppressing plugs, although many newer vehicles cannot accept them - check with your owner's manual or the dealer on this. A whining noise which varies with the engine revolutions is ignition noise, which is usually found in older vehicles.

If all else fails, there are various filters available which can be installed in line between the antenna and the radio and also in the power line just before the radio. If the noise seems to be electrical in nature and generated by the engine or electrical system, the latter should be your first choice, while in the case of static electricity or other noise not being transmitted via the radio's power line, the former may be the better choice.

Answer 3

Am Radio Noise

Answer 4

Wow, lot's of cool answers! Okay, here goes... your radio is picking up "noise" through the car due to the voltages going through your cars frame, block, etc.. All cars would have this noise if it were not for a "noise suppressor" built into the wiring somewhere. You need to find out where it is and replace it... yours is bad. Hope that helps!

Answer 5

i no how to fix your noise problem if u look either behind the alternator or down on the side of the distributor there will be a little cylinder shaped thing with one wire coming out of it this is called a condenser if it dies it causes a static noise through the radio you have to replace the condenser that should fix the prob

Answer 6

HAHAHAH Your engine has NOTHING to do with the reason why your car radio is having noise running through it lol. The Noise is coming from a bad ground. AS you drive off the sound gets louder and louder right? Its because of the bad ground that your radio is connected to. Trust me, I do customizing on car stereos for 12 years. I own a garage and all. email me if you need anymore help. [e-mail]

Answer 7

Without a doubt it is your alternator causing the noise. You will have to have a filter put on it to filter the noise out. Check with a mechanic. Good luck. Pops

Answer 8

Well your radio should make noise. The reason why it's making noise is because you are playing a CD or the radio.

Answer 9

You need to get new spark plugs.The ones you have now are the wrong ones.You need the resister type plugs.If you don't have resister type plugs in your motor,you will hear every RPM.
The noise is like a humming sound,and the faster you go the louder it gets.

Answer 10

need to put a noise suppressor on alternator and one on the distributor.