The red LED light on my safe-T-beam box (source) is off. I checked the wires to the box has 12VDC. I open the box and check pin 1 of the IC 34198A is 2.2V when the input power is 12VDC. It is too low. I increase the input power to 24VDC, and the LED light start to blink. I am wondering what the supply voltage should be for the safe-T-beam boxes. Does anyone know?