interrupt/counter

no, it didn't seem to fix the issue.

here is my full code as requested

/* infra red proximity detector by, Landon Williams
  teensy 3.2  and   AMG8833
*/

const byte dimmerSwitchISR = 9;    // temporary switch for counter. counter is pwm for led dimmer
volatile byte dimmerCount;               // track button press
byte dimmerValue;                // set PWM with counter 0-3
//volatile byte Dim;               // interupt name
byte ledRred = 3;               // red LED right side
byte ledRyellow = 4;            // yellow LED right side
byte ledLyellow = 5;            // yellow LED left side
byte ledLred = 6;               // red LED left side
const byte irA = 21;            // middle sensor, address selection
const byte irB = 22;            // right side sensor, address selection
const byte irC = 23;            // left side sensor, address selection
int battSensor = A0;            // read battery voltage, pin 14 on teensy


void setup() {
  // put your setup code here, to run once:

  // pinMode(dimmerSwitchISR,INPUT_PULLUP);

  pinMode(ledRred, OUTPUT);
  pinMode(ledRyellow, OUTPUT);
  pinMode(ledLyellow, OUTPUT);
  pinMode(ledLred, OUTPUT);
  pinMode(irA, OUTPUT);
  pinMode(irB, OUTPUT);
  pinMode(irC, OUTPUT);
  dimmerCount = 1;

  attachInterrupt(digitalPinToInterrupt(dimmerSwitchISR), Dim, FALLING);
}

void loop() {
  // put your main code here, to run repeatedly:


  /*if (digitalRead(dimmerSwitch) == LOW){
      //dimmerCount++;
    }*/
  if (dimmerCount == 3) {
    dimmerCount = 0;
  }
  if (dimmerCount == 0) {
    dimmerValue = 40;
  }
  if (dimmerCount == 1) {
    dimmerValue = 115;
  }
  if (dimmerCount == 2) {
    dimmerValue = 255;
  }

  analogWrite(ledLyellow, dimmerValue);
  analogWrite(ledLred, dimmerValue);
  analogWrite(ledRred, dimmerValue);
  analogWrite(ledRyellow, dimmerValue);
  delay(160);


}

void Dim () {
   dimmerCount++;
}