Static on radio

[N106FM]

I have a 2006.5 optima with the antenna built into the rear window. I have had static on the radio(worse on AM) since the car was new. The dealer could find nothing wrong.
Today I discovered that if I turn on the rear window deforster the static goes away. It doesn't come back after turning the deforster off, unless I shut the car off.

[Curtis Colee]

Attennae work on a large ground plane principle. For instance your car radio actually has a larger ground plane than your house radio. (the house radio runs on the AC chord ground where the whole metal body of the car is grounded to the battery) Anyway, I would look at all the grounding connections. If you think about it, your rear window defroster is nothing but a dead short between positive and negative (or ground). Could explain why the ground does not come into play until the defroster sets up the connection.

[joewb]

The antenna in the Optima is a power antenna. If it is not on you will have bad FM and virtually no AM reception. You may have a wiring problem because turning the defroster on also seems to be turning the antenna on. Turn the defroster off and see if the reception goes away, then you'll know.