I have a 97 Mountaineer with the JBL stereo system. The radio reception is terrible. The antenna runs the length of the vehicle and plugs in a box in the rear and regular wires run up to the radio. When I unplug the antenna in the back, the reception dosen't change. I've tried another antenna in this jack with no difference. Anybody have any suggestions? Thanks.

 

Sounds like a bad connection. Did you check the connection at the radio? Perhaps during a service it was pulled loose.