I put an aftermarket stereo in my 05 Mountaineer. It works fine except when the heater or A/C fan is switched to 3 or 4. The stereo stays lit but the sound cuts out. Guy from Crutchfield said there might not be enough power available and that I may have to use another power source (from the wipers or something). Anyone else experience this issue or know the best way to tap into another power source?