'90 V1500 something shorted out

[b79holmes]

Hi all,
A few days ago, I replaced my alternator and completely forgot to disconnect the battery. It seems something blew. It looks like I don't have power to any of the 'always on' circuits. Only the brake lights and hazards will work with the ignition off. None of the interior lights work at all, headlights don't work and no horn.

With the ignition on, the radio speakers will make static but the controls/display won't work, the wipers work, turn signals work, parking brake warning light/seatbelt light work, and the blower motor works. If I try and start it, it will crank all day long but it shows no sign of firing. I haven't yet checked if this is because of no fuel or spark. The check engine light will not come on at all, even if I put in my code reader.

I have checked the two fusible links by the starter, the two that come off the firewall junction, and the one by the alternator. The ohmmeter shows current can flow through all of them, and the firewall junction did register 12 volts on the multimeter. The connection between the alternator and the battery, and the battery to all of the nearby grounds are solid.

So what else am I missing that could cause these symptoms?