Ok have a '03 Legacy GT sedan with the antena built into the upper part of thye rear window.  However I have noticed this winter that is the rear window defoster is on no AM or FM stations come in AT all?  Is there a fix for this?

Does the defrost still work?

Probably a bad ground for the antenna, or the antenna wire shielding is shorted to the center signal wire or to the antenna grid on the window.

 

Check the antenna cable for continuity from the outer to the center pin, there should be none.

Ok, I will check it and yes rear defrost works fine.  Also radio signal is great as soon as a turn off the rear defrost, soon as I turn rear defrost on can't get any signal?

Rear defrost is a big source of RFI.

 

This could even be caused by a poor ground connection for the defrost grid, but that means pulling out the rear seats and pulling down the rear trim to get access to the wiring for the grid.

 

The antenna cable can be checked pretty easily by pulling the radio out, or by reaching up behind the radio of your hands can fit.

Thanks guys going to try pin this down soon.

Your car is equipped with the NSA blocker option fitted to some former Japanese embassy cars