What's wrong with my car radio?

General Questions
#1

I have a CD player in my car (I can get the make & model if it’s important, but it’s outside now). It’s got one of them detachable front pieces to it.

Recently, it re-developed a problem that had occurred a couple years ago and then gone away. When I first get in the car, the radio works fine. After a couple of minutes, however, the radio develops a static “stutter”: there will be a split second of static followed by normal reception. Within about a minute, this stutter will almost completely take over the sound, so that I’ll get only a split second of reception every five or ten seconds.

The CD player works fine when this is happening.

At first, I thought it was because of rain: I thought the first time this occurred was after a heavy storm, and I figured that maybe some water had gotten into the system and was vaporizing when the radio heated up and condensing on a circuit somewhere, temporarily shorting it out. But it’s been a week or so since it’s rained. Then I thought it was because of the heat (we’ve had a heat wave recently), and that whenever the radio got too hot it was failing to work for some reason. But this morning, while it was still cool out, it stopped working as I drove to work.

Is this a common problem? Is there an easy solution?

Daniel

#2

You may have a loose wire in the antenna connection.
You may have a bad ignition wire or spark plug.
Something internally in the unit may have a bad connection, including a crack in the circuit board. Try it with the car not running to to rule out an ignition noise.

#3

Do you have an electric antenna?
If so the mast may need cleaning. You need a rag (clean) and some WD-40.
Fold the rag, hold it behind the antenna and spray the mast with the WD-40. Then take the rag, and wipe from the bottom up. When the antenna appears clean and shinny, cycle the antenna up and down a couple of times. Re-spray and wipe. Lather rinse repeat until the mast comes out clean after cycling.

For any mast type antenna, (electric or manual) there is a nut at the bottom of the mast. Check to make sure it is tight. If the nut gets loose, or rust develops on the underside of the body right there, the antenna won’t ground, and you get static. Be careful tightening, you can break things here. This isn’t a lug nut, just an antenna nut. Good and snug is all you need. Maybe 10 ft. Lbs.

#4

Thanks for the ideas, folks! I’ve done a little more investigating and experimenting:

-The radio, if it matters, is a Sony XPlod 50WX4.
-I tried leaving the radio on in the car with the key in the ignition but the ignition turned off. WHen I checked back 15 minutes later, the radio was full-on static. (If it matters, just before this experiment, I moved the car out of the driveway, so the motor was running for about half a minute).
-The antenna is on the driver side and is not electric as near as I can tell: it certainly does not retract automatically. There’s a little plastic mount thingy attached with two screws, and I can push the antenna in or pull it out to its full length; I can also rotate it freely.

If it matters, the car is a 1995 Geo Prizm.

Daniel