Player boots, display is fine, player program starts, dimmer drops low and becomes erratic when adjusted with either the knob or buttons- From Drakino.

This is all due to the same problem. When you boot your player and senses that your headlights are on, it is going to dim the player to whatever you have your dimmer set to. Say 70%. When the player is COLD and it tries to set it to "70%", it will randomly select a brightness level. If your player is WARMED UP, it will actually set it to 70 percent. You will notice that if you have the problem when your car is cold, sometimes it may even dim the display to the point where you cannot even see it. If you wait till the player warms up to over 24 deg C or so, you will notice this problem goes away. You could wait till the player warms up and turn your headlights off, then back on. You will notice that the dimmer will now function to whatever you have it set to....

If you could, next time you turn your headlights on and notice that your player dims to the wrong brightness level (assuming your car and player are cold), leave your heat on full blast to get the player warmed up (in my truck it takes about 20 minutes). Then turn your headlights off and on, see if your dimmer is actually what you set it to, then try adjusting it. I bet that when you try adjusting it after the player is warm, the dimmer will no longer be erratic...