What might cause excessive static on my AM radio?

Dear Car Talk | Mar 01, 2001
Dear Tom and Ray:
RAY: Well, we can suggest some very fine FM stations, Tim.
TOM: Actually, your problem is not AM or FM, it's RF. Your ignition system is creating radio frequency interference (RFI), and it's being picked up by your AM radio.
RAY: RFI usually comes from the alternator or old, leaky spark-plug wires, and an RFI filter usually solves the problem.
TOM: Just hobble on down to your local Radio Shack, or a similar establishment, and ask them for an automotive noise filter for your AM car radio. It costs about 20 bucks and attaches to your radio's power line.
RAY: If you can't or don't want to install the filter yourself, any reputable car-stereo establishment ought to be able to put one in for you. And while you're there, you can avail yourself of their "noise filter and 17-inch roof-mounted monster bass speakers" special. Good luck, Tim.
RAY: Well, we can suggest some very fine FM stations, Tim.
TOM: Actually, your problem is not AM or FM, it's RF. Your ignition system is creating radio frequency interference (RFI), and it's being picked up by your AM radio.
RAY: RFI usually comes from the alternator or old, leaky spark-plug wires, and an RFI filter usually solves the problem.
TOM: Just hobble on down to your local Radio Shack, or a similar establishment, and ask them for an automotive noise filter for your AM car radio. It costs about 20 bucks and attaches to your radio's power line.
RAY: If you can't or don't want to install the filter yourself, any reputable car-stereo establishment ought to be able to put one in for you. And while you're there, you can avail yourself of their "noise filter and 17-inch roof-mounted monster bass speakers" special. Good luck, Tim.
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