At some point in the last few months the AM/FM reception in my 500 has vanished. I normally listen to DAB on an Alpine EasyDAB, but ocassionaly switch to FM in low signal areas and also use the traffic alerts.

I've done some basic tests, the aerial is plugged into the head unit and screwed into the base. I have tested with a standard aerial (76cm wire) and that improves reception.


There doesn't seem to be continuity between the aerial base on the roof and the aerial connector under the dash, so I'm thinking it is one of the following:

1. No phantom feed going to the aerial from the headunit.
2. A break in the cable/connector
3. A problem with the aerial

Does anybody know what the phantom feed should be? I measured 0.5v, but could that be the headunit detecting open circuit/short circuit and stopping the feed?

Are there any breaks in the cable? I've seen reference to a connector on the left of the car in a previous thread, but where exactly is this?

How easy is it to replace the aerial base? Is it DIYable?