Many batteries no longer have a place to connect the sensor. If not connected, the warning light will cycle.
The sensor needs to see a certain voltage to work. Two options as I see it:
- Get a new sensor from the battery distributor and try it in each cell till the light goes out.
- Run a 10K Ohm potentiometer from a switched 12-volt lead to ground with the center terminal attached to the sensor lead. Adjust the potentiometer till the light goes out.
Others have simply connected the wire to the battery + terminal without problem.