My AM reception is poor. I've never had this problem in my lifetime. Has to be antenna in rear window. Any ideas?

 

Off the top of my head, some common causes could be a loose or corroded electrical connector for the antenna behind the E-pillar trim; a loose or corroded radio ground (probably in the center console area but I'm not sure); interference from EMI or RFI sources in the areas where you drive (AC power lines, electric motors, mobile phone towers, radio towers, etc.), or an electric component in your car that is generating more electromagnetic interference than it should. If the noise in the AM is worse when you open or close a power window or run some other electric motor in the car, there may be a problem with the shield of the cable between the antenna and radio unit. Most vehicles have capacitors on the coils and alternator to suppress electrical noise, but capacitors can weaken over time and loose their protective capability.

That's all I can think of for now, but perhaps others will have some more X350-specific ideas.

Cheers,

Don

 

I had the same issue....
Remove the pillar trim on the driver side rear panel. Between the rear door and the back window. Where the seatbelt passes through. You will see a small white "box" where the rear window antenna cable attaches. This is the amplifier.

check that connection

good luck
Tom