Did you change your battery because your original was totally dead? when you turn on your bike, can you toggle through your display until you see battery voltage, or is your system voltage now too weak to even do that? Do you have a voltmeter? If so, check your battery voltage at the posts. Double check your connections are OK. If your connections are good, and now your battery voltage is low, you probably have a bad voltage regulator.
Your bike will need around 11V before your display will start working properly, and about a minimum of 11.8V+ for your bike to turn over. If you battery voltage is low, and after charging you can start your bike back up, look at the displays voltmeter, it should read 14.5 +/- .3 V when the bike is running and charging. If your voltage doesn't change when the bike is running, chances are your regulator is bad.