Tricky Stereo Question... Dimmer Switch??

OK... I have an aftermarket stereo installed on my 99 rodeo. I used to have two (professionally installed) amps hooked up, now I only have a small amp connected to my inside speakers.
Everything was running great until one day I noticed the static in the speakers getting a bit louder. Then a month later my radio's illumination and amp would not cut off (with the car turned off). I soon realized that without removing the main fuse to the amp my battery would drain overnight.
Now, I want to wire the radio directly to the speakers (like factory). I thought this would cure my problem. I wired everything like I thought it should be and it seemed to be working fine until I got in my car that night. My dash lights weren't working. I screwed around with it for a while and came to realize that when I grounded the dimmer line (coming from the dimmer switch) I got my lights back. So, I ran a new ground, grounded the radio and dimmer lines. It works now but it will not dim and I have some mad static from the speakers..Normally static is caused by a bad ground, or a loop ground, but I still can't find it. It is possible my cd player is the prob.. (Old Eclipse)

I am wondering if there is a fuse on the dimmer swich line that would cause it to do this. Is my dimmer switch bad? Am I just overlooking something? Help if you think you can.. Thanks for looking.....



**Updated** I found one thing after searching online. The small ground wire that runs off the main ground from the battery had a prob. It was grounded to the battery tray. The tray had been corroded over the years and apparently did not provide an adequate ground. I found a nearby bracket that was screwed into the body and I grounded there (after scraping off the paint). My radio noise went away but I still have problems with the dimmer switch. I currently have darker-than-usual dash lights that won't dim. The only way I could get the dash lights on was to ground the dimmer wire coming from the factory stereo wire harness. Still would appreciate help..

Have you tried to remove the radio all together? I if it is the radio the problem will stop. Unplug the radio and make sure no wires are touching each other or grounding out to metal. If you still have the problem after removing the radio and unplugging the wires from it then you have a problem elsewhere. Also if the amps were mounted in the back make sure a screw did not go through any wires on the floor of the vehicle. I was an installer for 15 years and this was a problem i found that many people did when installing...running screws through wires...also check all of the fuses, not just by looking at them but with a test light or digital multi meter. Sometimes a fuse will look good but will not transfer a good 12v current.