I just tried to listen to a football game over the weekend while I was heading down to the Seahawks game, and I found out that my AM reception is weak as hell. FM works fine - coming through loud and clear. Just AM reception, and it was the same across the 2 or 3 stations I tried.

Any ideas on this? I used the nissan antenna adapter when I put the HU in. I am not finding a lot of good leads on troubleshooting via google searches.

 

The usual problem with reception after aftermarket install is that the antenna amplifier doesn't get plugged in, since people see the "Power Ant" wire and figure they don't have a power antenna so they don't need it. Since you say your FM is just as good as before, either you're in an area with exceptionally strong FM so the fact that your antenna amp isn't connected doesn't matter, or your antenna amp is fine, and there's possibly some damage to your AM antenna.