Sudden AM radio static
 

All of sudden last week my AM radio started to have much more static. I guess it could be my biodegradable wiring harness finally giving up, but I am kind of hoping it might be a common symptom of needing a new battery or alternator or something. I never had great AM, but all of sudden it got much worse. I can even get synchronized static with revs from the motor, which never happened before. I can also hear changes in the static when I mess with the AC controls and maybe other electrical things.

I can live without my AM radio, but I am afraid it may be a symptom of some other problem. It just seems weird that it changed quite suddenly. One day I started up the car and I had more static. First I thought it might just be a bad reception day, but it has continued for over a week now. It seems it must be something with the car. It has been about 5 years since I replaced the battery, so I am wondering if that could be the problem. If the battery needs more work from other electronics to keep it charged could it demand extra current that ends up in my AM radio? I may get a new battery anyway, since we are going into the winter and I have always read that it is good to replace the battery on a regular basis.

Any ideas would be appreciated.

AM static increase.
 

A number of years ago Cadillac had a radio noise problem that was caused by a 'bad battery' . The battery would operate / start and do all that it was required to do but was the noise source.

Since you are using a very elderly battery and mentioned that you were going to replace it anyway that would be the first step.

You mentioned that 'fooling ' with the AC seemed to change things.

Is the static there when the car engine is not running ? What happens static wise if you turn on the lights with no engine or anything else running?

If you can isolate the radio DC power supply ( another battery clipped to the 12 volt DISCONNECTED POWER LEAD ) with nothing else operating and there is no static you have to look at the rest of the cars circuitry.

Finding the cause of 'static' is a matter of observation, disconnecting and isolating components and observing the effect.

Islandmerv

Thank you for the reply. I am slightly encouraged to hear that a bad battery caused an issue for you.

With the car off there is little or not static. There is static with the car off but ignition on and running the fan with or without AC compressor engaged. I think my lights also hav an affect. In fact it seems everything affects the AM radio now, but it certainly wasn't this bad in the past. The thing is that it became worse suddenly. Everything else seems to be the same, but the AM has much more static.

AM reception is very sensitive to shielding of the ground of the antenna cable. A break in the shielding can cause the symptoms you describe but FM will still sound fine. Good luck.

More on 'Static"
 

There are lots of different types of static.

Some are caused by ignition and sound like a small machinegun, some are scratches that continue in long bursts.

You can investigate a bit more with a small portable radio to see if the noise is coming in 'over the air'.

The alternator will make a siren type whine whcih increases in pitch as the RPMs increase.

You don't describe the type 'static' you are experiencing.

If you are married you will recognize different types of Nagging. Some is continuous, some comes in bursts, some is subliminal. All are annoying.

Same with static. You have to describe the sound and note what is going on at the time the racket started. :rolleyes:

Islandmerv

I do have the siren type, although that is not the only type of static I have. I also have a continuous background kind of static. I did not have either type of static a week ago, well at least it has certainly become much worse recently. Once before I lost a battery and I was hearing a ticking sound all of the time. It turned out to be the alternator or the voltage regulator trying to keep the battery charged. Since this started suddenly and I knew my battery was getting old, I just wondered if it could be related. It sounds like it could be related and I think I should go ahead and get the battery any, so hopefully it will go away if I get a new battery.

Fortunately my wife is not the nagging type. :) My wife really is pretty good, she certainly seems to have less problems than my ageing W124.:(

Thanks for your comments and I did appreciate the humor ;)

I know my wiring harness must have all kinds of breaks, so I guess that could be the problem. It was just a little weird the way it started rather suddenly

Thanks for the tip.

Actually, the shield is braided so it's more likely to happen at a connector. Hope this helps.