Radio Static

[Mguyross]

When Rear Window Heater is on I get Static on Radio. On = Static, Off = No Static. Any thoughts?

[tunnanxwd]

You have a short somewhere along that line.

[9-3 Aero]

Wagon or sedan; In case of the latter is the window heater a part of the FM antenna, including a filter.

[Lucas Cowell]

I'm having the same problem with my 9-5 sedan, what should be looked over in the car to source the problem?

[9-3 Aero]

The window heating includes relay B in dashboard relay box, the antenna amplifier, heating element and a filter, and of course wiring.

So it depends, is there static when the alternator (engine) is not running? If so, at least "noise loops" (very common with the old DC alternators) can be ruled out.

The relay can have a contact problem.

The audio amplifier could have a problem, or there could be a weak contact amplifier / heating element / filter / gnd. The latter could create "sparks" due to the current load when the heating is on. In case radio FM reception is weaker than it used to be, it may confirm source of the problem being here.

I guess the signature of the statics, is it uneven or not, may point towards the area where to start looking for the suspect.

[Mguyross]

Thank you, I will begin checking out the problem with engine off and try cleaning the contacts on relay. I'll get back to you with the results. BTW, it is a sedan.