I have a stock stereo in my 2002 Trooper. Recently the FM reception has been horrible. Mostly static, and search wont find any local stations. (There are dozens) I thought it was a bad head unit, so I purchased an identical used tape player head unit that sits on top of the 6 disc changer. The newer used head unit also does not receive any FM channels. Only some really strong channels come in poorly. I have verified all the connections, and both of the diverisity FM plugs are plugged in. I have checked all known fuses. DO I have a bad diversity amplifier, is there such a thing? What should I check next?