Speakers popping

[KMACD71]

I have speakers in my doors and they started making a pop noise when I power up or turn off the stereo. The sound quality fades in and out. I am trying to narrow down the causes and have started with the ground. The previous owner had the stereo ground(black wire),grounded to the fuse box screw. I tried to ground it to the wiper motor screw and can't seem to get sound from there. Am I going in the wrong direction here? Could it be speaker related instead of ground related. Any advice would be appreciated.

[AceX]

I doubt its speaker related. get a ground that isn't really attached to anything that might be intermitant. Look for a grounding point on a bracket somewhere.

[KMACD71]

I was messing with the wires again .To my surprise while testing the sound with the ground wire not attached anywhere, I am able to play music. Is this normal or is black wire not my ground? Also I am still getting the pop or bass boom when I change stations,switch to C.D. or turn the unit on or off. Sounds good otherwise.This isn't a new install, it's been running fine up until a few days ago.

[AceX]

the pop you hear is from the amp, be it in the deck or external. There's a pop sound when the amp turns on or switches sources.

I'm going to go look into it a bit more right now. Get back to you soon.