What connections can I check to diagnose my FM signal strength?

I have heard that the rear windshield antennas are bad for signal in general, but I get almost no stations at all.

Is there a connection or connections I can check to make sure they haven't come loose? Where are those located?

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 1
crwdns2934285:0crwdne2934285:0