Ever since i bought my car(1999 Ford Focus mk1), the volume of the standard car stereo(6000cd rds e-o-n) has ben turning itself down and up again over time.
When the stereo has been off for some time, having the volume on 5 will be sufficient. After a while, volume 5 will be too low and i turn it up to 10 to get the same volume as before.
It also has sudden blips where the volume goes back to normal.
it doesn't matter if the engine is on or off
Read more: Car stereo volume decreasing and increasing over time
