Leaderboard

I see that your head unit and adapter connect using RCA plugs. I haven't set up a head unit like that, but the first thing I'd do is poke around in the owner's manual to see if there's some some setting you need to change to switch it over from the internal amplifier to the RCA outputs. I would also double-check that the RCAs are plugged into the correct holes--looks like you want the four closest to the power plug on the back. If it's not that easy, check fuse #4 (15A), in fuse box JB (looks like that's the one under the dash). That's the unswitched power feed for the audio system, and while the head unit may power up without it (it also gets power from the ignition switch), the audio amps (there are actually three of the little blighters) will not. If that fuse is blown, check your work, because fuses usually blow for a reason. Check your color code match-ups, look for damaged insulation/slipped-off heat shrink, make sure the pins aren't folded over in the adapter plugs, and make sure you didn't pinch a wire when you bolted the radio back in. If the fuse is good, and you test from the yellow wire in the head unit plug to ground, and you should see around 12v whether the key is on or off. The only other thing I see that could take out all the amps at once is the turn-on signal from the head unit, the one you mention in your second post. It should be blue/white coming out of the head unit. Confirm that this connects to the light green/red wire in the harness, and confirm that it tests at +12v when the head unit is trying to play music. If that checks out, I would try and track down the relay for the front speakers to confirm that it clicks when the radio turns on and off, or find the rear amp and verify that it's getting signal to the appropriate pin. The circuit diagram for the Bose audio system is on EL-145 of the '99 manual (download it from Nicoclub if you haven't yet).