I've got a 2000 blazer ls 2dr 4wd. A couple of months ago I installed an Alpine ida-x100 and some S-series speakers and everything was working just fine. 2 weeks ago or so I ran a 4 and 8 gauge to the battery for some amps along with disconnecting the factory speaker wires and running some new 14 gauge monster cable to the back. When I powered everything up I got nothing. I reconnected the factory radio just to make sure the Alpine was still working. I got no display but it would attempt to eject a disk or cassette. The speaker wires were unconnected so I couldn't tell if there was any sound. I tested the red power line going to the radio and it was fine and I looked at all the fuses in the fusebox and couldn't find any blown fuses. I just noticed that the overhead console doesn't show a display when the key is in the run position but will show a display when it is in the accessory position. If your still with me, thanks, and do you have any idea what it might be?

 

You ran 4 and 8 gauge from the amp straight to the battery? (1) 4 gauge and (1) 8 gauge?

Electrical diagnosis 101. When something fails upon installing new device, remove newly installed said device and retest.
Disconnect the new amp wires and see if you can duplicate the results. Then disconnect the new monster wires and test again. Something happened during the install of these wires.

 

I never installed the amp. After running all the wires I put everything back together and just tried turning on the radio, just to make sure everything was ok, and it wasn't.

 

Thread closed --> Original thread on the subject: Install problem