01 Tahoe has remote start runs for a few seconds then shuts off speedo reads 100 with disconnected battery

 

my 2002 Tahoe 91K 5.3 lately crank weak at the morning only battery is New optima Red top battery I even disconnect night before both terminals and I put the battery under charger next day same just in the morning weak cranking then starts and the rest of day start okay possible starter going bad? any advice please