I am running (4) Pioneer TS-A1795's off of my Pioneer P-2000 head unit. The HU puts out 12x4 watts constant and 22x4 watts peak. If I turn the volume up to 2/3, which is just around the peak volume I can get without distortion, and with the bass all the way up, the CD player display dims. If I open a door and let the courtesy lights come on, they all dim to the bass too. Some people have been skeptical about the ability of just my CD player to do this, but I can tell you that it does it everytime. Someone suggested running a larger power wire to the CD player to fix this problem. Is that a good idea, and what size wire would I use? Any other ideas? By the way, I am using a Crutchfield wiring harness to connect the CD player, so all of the connections are solid and tight.

 

that's pretty normal. The power wire that feeds your fuse block (which feeds your stereo and interior lights), is only a 10 awg or so. when the stereo is outputting quite a bit of power, it causes a voltage drop across the input power wire- which you see as the lights dimmming on the head unit and the interior lights.

A couple fixes: 1. install a small capacitor inline with the head unit, and stuff it under the dash.. 5-10,000uF, 20V.

2. run a larger power wire from the battery to the fuse block, and hope the problem goes away.

3. live with it. it's not that serious anyway.