I have now also lost AM receiption
.
I did some research and troubleshooting, but it didn't resolve it. Here is some extra info (incl pictures, which this thread lacks):
Picture 1 is the Antenna amplifier that's mentioned on Page 1 of this thread. It's behind the tailgate trim on the Wagons. The pages from the Service Manual that Ric posted suggest testing continuity of the 4 connector contacts to the Amplifier Body (>10kOhm). I did that, and mine tested fine.
Picture 2 Shows what paulw11 mentioned in the previous post. Wires inside the tailgate rubber boot can break (more so in the Pre-facelift models from what I have read). I checked under both rubber boots, and didn't find any broken cables.
I confirmed that by measuring voltage at the power connector on my wagon's Antenna amplifier (I needed a thin wire to get into the contact). I have 12V, so no issue there.
So I suspect it's an issue inside the Headunit. While I'll gladly spend $1000s on mods, or a few hours fixing the headunit's AM Board (if there was a known fix), I won't be spending ~$400 just to get AM Radio back
. And instead of risking a 2nd-hand unit where the CD Stacker could fail at any moment, I'll stick with my working CD Player.