Pontiac Repair: 1998 grand prix gtp, voltage spike, correct temp

Question
I changed the battery in my car. After i changed the battery
the outside temp readout on the dash will not reset. When i
start the car it starts at -10 or so and goes up in temp.  

Answer
Hi Mike:

Is the read out on the Mirror or on the HVAC control head? does it eventually read the correct ambient temp or not? If it's just skewed low I would venture to say it's a temp sensor that is bad but if it starts at -10 and then reads up to the correct temp I would say it's a bad mirror or Hvac control head maybe a voltage spike took or either component. good luck :)