please help me :(

I just bought a 1999 Aurora today, and I was putting the aftermarket stereo from my 1995 Aurora into it. We went to go pick something up, the doors won't lock with the door switch, they'll unlock though, none of the buttons on my transmitter worked, so i decided to try to plug the computer in the back of the car in. As soon as I did this, my lights dimmed, my temperature, speed, and RPM won't be measured, and my driver information center shows nothing, and I can't control my temperature.

please help me fix these problems :(

Also, the "Hazard" light is lit up extremely dim.

i own a 92 olds 88, and the problem you described isn't all that uncommon. odds are that number one, the wiring harness was changed in the years from 95 to 99 (only takes one wire changed), number two, one of your wires is shorted and when you went to install the head unit moving the wires caused it to ground itself, or number three

if my hunch is correct, it is probably a short. if your lucky it's in the radio harness (before the plugin leading to your head unit). if your not lucky, it could be a wire from any of your electronics, grounded through moving it around while installing your stereo.

does the old one still work if you plug it in?

if it does, then the first situation is probably the cause