Speedometer not working at all.

I have a 01 Taurus SE FFV and the speedometer isn't working period. I just started driving this vehicle and It's been sitting for a year but has been started in that time. There was a burnt (electrical) smell when an attempt was made to slow charge the battery but said battery was replaced after not taking a charge. Car started fine with new battery. 2 days ago I started to drive the car as a daily driver and noticed that the speedo wasn't working. When I got to work, I hooked up our diagnostic scanner and it gave me a long list of codes, they are as follows.

B1318 Battery voltage low;
voltage currently at 12.8
B1342 ECU malfunction

C1223 Brake lamp warning output circuit Malfunction

B1426 Seat belt warning lamp circuit short to battery;
chime/dash light works
B1325 Door ajar warning light short circuit to battery;
dash light works
B1438&B1450 Upshift selector/wheel plus switch malfunction. Low input