Random gauge lights and power loss to certain interior

Hello! Recently my trailblazer shut off on me shortly after replacing front suspension, roughly one day later. Turns out the ignition switch went bad. Replaced the switch, car starts no problem now. On the way back from getting an alignment because of front suspension replacement, the car started having flashing lights on the dash. First it was the Traction and Stabiltrax lights, which I thought were just from the alignment. Then shortly after, the ABS and brake light come on and off intermittently. Then randomly, the Car Security light, the battery light, the airbag light sometimes, and also the radio goes in and out as well as my gauges for battery, temperature, oil, and gas all go normal, then drop, as well as the power bank for the drivers side window/lock controls. Took the car to AutoZone to have it scanned and they said the alternator was half failing specifically the voltage regulator, so we replaced the alternator. Car still starts no problem and runs fine, but all these lights still come on and off as well as the erratic gauges and windows/locks. Checked the ground wire under the drivers side and the ground to the Cluster in the passengers side. I am riddled, and by no means am I a mechanic, but my step dad is and he is the one who has helped me replace all this other stuff. Any ideas? I know there's a lot of variables and information. It is just one thing after the other.