I was troubleshooting a charge indicator circuit on a tire inflator/flashlight. The green LED is supposed to light up if the battery voltage is above a certain voltage level. The LED is connected to one of the outputs of an LM339 Quad Comparator. The corresponding (-) input to that output was connected to the circuit tracing back to the battery, but the corresponding (+) input just seemed to be floating. I couldn't see any traces off of that pin going anywhere. According to the 339's datasheet, output will go HIGH (with a pull-up resistor) if the (+) input voltage is higher than the (-) input voltage.
My question: With the LM339, if the (+) input is floating, does the IC have a set percentage of VCC to "make" the (+) input?
I'm not a pro at searching through datasheets, so maybe the answer is staring me in the face and I just missed it. I am as sure as I can be about that pin not being connected to anything on the PCB, though.