Radio reception issues

[3SheetsDiesel]

I’ve got a 2004 Subaru Impreza wagon.

Topic

[dreamer2355]

The spark plugs you use, are they the resistor type to reduce radio suppression?

Do you have any subs in the trunk?

[3SheetsDiesel]

I’m running factory recommended NGK double platinum plugs. I had a pair of subs at one point in time, but don’t anymore. I haven’t made any changes to the car since before the radio stopped working right.

[Matt]

I would look for a crack or break in the wiring going to the hatch then, around the area where the wiring is exposed from the body to the door panel.

[EricTheCarGuy]

Yea this is a tough one. First are you having poor reception with AM or FM? AM is amplitude modulated meaning that the closer you are to the source of the signal the better reception you will get therefore if you are around a lot of obstructions like mountains, buildings, power lines, or lots of trees this will interfere with the signal. FM is frequency modulated and does not have these issues as a result, so if you’re having trouble with AM stations particularly since we recently had a coronal mass ejection (solar flare) from the sun radio reception will be an issue and there may be nothing you can do about it.

If you’re having issue with an FM station the first thing to try is a different station, if it still has issue with other stations then look to the antenna and it’s leads, as suggested there could be a break in the glass somewhere. Many times they also put an amplifier/suppressor in the circuit rear defroster to prevent interference form the rear defroster, if this is having a problem it could also cause an issue like that and it can easily be checked by turning the rear defroster on and off to see if the signal gets better or not. As mentioned the ignition system can sometimes cause a problem with this but that’s not as common as it used to be. There is however a suppression circuit in the alternator as well as the fuel injection system to help keep radio/electronic noise down on most vehicles, you’ll have to consult with your service manual to see if that is a possibility on yours, this should also contain the testing methods that you could use to check these things should you have them.

[twiggy]

When the car is moving the moving air over the rear glass will cause an airplane wing effect and pull up on your glass. I would try pushing up on the rear glass manually to see if you can replicate the problem. If it is a hatchback try opening the door too to stress the wiring to the window.

If all that fails try disabling the speed controlled volume if your car is equipped with it.

Last thing to check is if you have continuity between the chassis of the radio and ground.

[djdevon3]

Those are all awesome suggestions. Only other thing I can think of is the accelerator arm rubbing through a wire.

[Author]

Replies