TLC372 comparator setup
As mentioned previously you have connected the battery the wrong way around and you may have damaged the comparator. Try the circuit below with a an unused IC.

Note that if you fit the LED and R3 you will not need R5. However, if you leave out the LED you will need R5. Most comparators have an open-collector output, (or for CMOS IC's an open-drain output). This type of output can only sink current, it cannot source current. An open drain output is often used with a pull-up resistor (R5) so that the output can both source and sink current.







simulate this circuit &ndash; Schematic created using CircuitLab