2005 impala has no dash lights at all,exeptthe

Possible bad fuse or bad light switch.

that is weird, could be a squeak in your hvac fan, see if it changes with speed of fan, usually a beep is accompanied by a light on the dash as well

I think Autozone will scan your car for free. Pretty sure you have to scan it to get codes.
One problem is probably affecting the other.

Check your water pump or heater coil.

yahoo

Connect a scanner or code reader,anytime you get a light on dash,to diagnostic connector under dash,and read code.

Most likely a bad Wheel Speed Sensor.

if the rest of your dash and instrument lights work and it's just the speedo that stays dark you have a bulb burnt out in your dash cluster.

check for blown fuse(s). Seems like you tapped into the backup light circuit.

Same thing happened to my Chevy impala, I slapped the hazar switch located on the dash, quite hard and it stared working!!!!

sounds like the tire pressure monitor light it means you have a soft tire check the psi in all tires and make sure they are all the same if so one of the sensors could be bad if so you willhave to take it to a shop to be tested for which one is bad and to have it replaced as it is inside the tire