Radio Static

My '97 Jimmy has a great deal of static on the radio when the engine is running. If the engine is off no static can be heard. If the CD player is running there is no static whether the engine is on or off. The volume and possibly pitch (not certain) of the static increases with engine rpm. Any ideas?

Old wires, old plugs, bad grounds. Or just a 20yr old radio going out.

Old wires, old plugs, bad grounds. Or just a 20yr old radio going out.

Do you mean spark plug wires? It's been at least 10 years since they were changed. Is there any way the alternator could be at fault? The volume change with rpm makes me suspicious.

[QUOTE=mwaldrp;7195774]Do you mean spark plug wires? It's been at least 10 years since they were changed. Is there any way the alternator could be at fault? The volume change with rpm makes me suspicious.[/QUOTE

Spark increases/decreases with engine rpm. Wires much cheaper than an alternator. But it could be. If your wires are 10yrs old, how old are your plugs?

Have you done anything with the headlights? LED and HID lights have been known to cause radio interference.

Spark increases/decreases with engine rpm. Wires much cheaper than an alternator. But it could be. If your wires are 10yrs old, how old are your plugs?[/quote]

It's probably been 8 years for the plugs. They haven't given me any trouble so I've just let them do their thing. It's probably time for new plugs, wires and distributor anyway. Any other parts I should just go ahead and replace?

Have you done anything with the headlights? LED and HID lights have been known to cause radio interference.


No headlight changes. Thanks for the suggestion. I did not know this was an issue with LED and HID lights.

There are noise isolators (basically an antenna filter) you can install that should cure your issues.

If you haven't done a tune up in yrs..It's time for it..

ignition noise in the radio is from arcing in the ignition system. usually from spark plug wires . the wires on old vehicles is in need of new loom and proper hold downs .higher than normal resistance of the plug wires causes this also or open in the wire silicon core ..

the spark plugs spark in the engine this is not causing this because the spark is in a enclosed metal bore. then the other reasons usually are arcing ignition coil/bad distributor bearing/cap and rotor. if the rotor wobbles then the distributor needs replacing...

the hood also if not grounded well and it does happen because of rust allows this electrical noise to get into the antenna of the radio.. placing a ground wire attached to the hood helps reduce this .. but if those plug wires are arcing then that will not completely fix it.

make sure the plug wires you get have about 3K ohms resistance or less.

My '97 Jimmy has a great deal of static on the radio when the engine is running. If the engine is off no static can be heard. If the CD player is running there is no static whether the engine is on or off. The volume and possibly pitch (not certain) of the static increases with engine rpm. Any ideas?

I forgot to say the antenna wire coax maybe corroded. It has been a longtime since I had these issues and one time the antenna got corroded bad but not that you could see it. if the coax shield is corroded away that will reduce signal and pick up more engine electrical noise

So I'm an idiot. The antenna cable had worked itself loose from the base of the antenna which resulted in poor radio signal and static interference. Why I did not check this initially defies explanation. I reconnected the wires then secured them by wrapping the junction with some electrical tape and everything is good as new. I went ahead and replaced the spark plugs, spark plug wires, distributor cap and rotor since, as you all correctly pointed out, it was well past time anyway. My Jimmy is running well and I'm back to enjoying my music.

Thanks for all the help.

good you fixed it .

you posted the fix and this will help others .