95 Explorer EB FM Radio problem

I have a JBL sound system in a 95 Explorer Eddie Bauer Edition. The FM works part of the time. This is a AM/FM Cassette with out CD. The am works and the cassette works. The FM will scan to pick up radio stations but will not stop on any. I have tuned in a station that should come in and has not. I also have replaced the radio in the dash. Has anyone had this problem?