Help!! Instrument cluster/ high beams not working

Hi, I recently had a wierd problem. I went and fired my jeep up one night. Got in and suddenly all the lights went dim. Figured it was the Alternator since when I got home I tried to start it back up and it was completely dead. The next day I replaced the alternator. I went to start it back up and this is where I gets really wierd. While the key is turned to accessory the cluster lights up like it should but, when you go to start the jeep everything goes black. Not only that but now I dont have high beams. Could it be a blown fuse? Also have a few codes coming up. They are P1594, P0622, and P1687. If anyone could help it would be much appreciated. Thank You!

You replaced the ALT new? What brand/model. You should not be viewing 19 volt outputs.
Try another ALT, battery load test it if you believe that the battery is suspicious in any way.