ACS712 - Current sensor saw random numbers :O - Not working

Hi all,

I have a problem with current sensor ACS712. When I connect a 5V to 1.2k resistor, I saw uncorrect results in serial monitor, interestingly, when I disconnect to resistor, (I should see the 0) however, result is not changing. Actually, results are not like about current. I saw that random numbers in serial monitor.

Think that I have missing somewhere or sensor has a problem.

Thanks for your help.

Its my basic circuit without resistor.

When 1.2k resistor is connect.

when nothing is connect.

Also its my codes

float average;
void setup() {
  Serial.begin(9600);  

}

void loop() {
 average=0;
  for(int i = 0; i < 1000; i++) {
    average = (average + (.0264 * analogRead(A1) -13.51));
    delay(1);
    }
        Serial.println(average);

}

Please provide your electrical circuit diagram.