The volume in my 2009 Kia Sedona randomly decreases. I was driving and listening to the radio and all of a sudden the volume starting decreasing until it got to zero. I turned the volume back up and it did it again. I turned the radio off and after a while I turned it back on it worked fine for a while and then it did it again.

My 2009 kia sedona's volume is all over the place. Usually happens after driving atleast 15 min. The volume starts going up and down randomly to the extremes. All I can do is turn it off.

Not sure about your car, but they come equipped now with a program that will decrease the sound level due to the traffic around and increase the volume to compensate for road noise. The best thing is to look in your manual, under the radio section and see if there is a section for this issue. If so, it can be disabled. We have a car that does it and I flipped out when it started so I disabled it. Not alot of help but it will give you a little insight to a possible solution.