I have a 99 Ford Explorer, and recently let it sit outside for 3 months in a rainy climate when I was on vacation. The battery was dead, so I replaced it. It started up just fine, but within a few minutes the radio digital display became garbled, the radio started turning on and off, and the tape player started clicking. This clicking goes on for several minutes. When it stops, I can turn the radio off. But it will soon come back on again. Even after I park the car and turn the key off, it will come back on. I disconnect the battery when I stop now, but would like to find a way to fix this.