2000 caviler cd changer installation

Pioneer changers come with a short ground wire---just ground it in the trunk---plus, I'm pretty sure the changer will also get a ground just by screwing its body to metal.

BCM stands for Body Computer Module or Body Control Module, depending on which GM car you're talking about.  You will probably find ignition power at the BCM if you poke around long enough, but you're not likely to find accessory power there---which is what you want.  "Ignition" means it only gets power while the key is switched to Run, and "accessory" means it gets power when the key is in the Accessory and Run positions.  You want to be able to play CDs with the engine off, right?

Probably the easiest thing to do is just grab the main ignition harness under the driver's dash, open up the tape with a razor, and go for the thick brown wire in there.  Make sure you keep the Pioneer-supplied fuseholder in place----if your wiring should ever short out, you want just the Pioneer fuse to blow---not the car's big fuse that powers the brown wire.

Also, if you can think of any item in your car that only works with the key in Accessory or Run, then you should be able to get power there.  The problem is, I can't think of many things that work that way on a GM car-----cigarette lighter is constant, power windows are in Run only, power mirrors are constant.....you get the idea.