A/C Pump Sensor

[Flyrod1]

The A/C pump warning light is coming on forcing the A/C unit to cycle off, and then on, constantly.

My AC strainer picked up an inordinate amount of sludge the last two weeks and was clogged up so I cleaned it and I checked the water pump and it was clean.

But the sensor alarm light continues to come on and the unit to cycle off, then on.

I have an old Luminaire AC.

Any thoughts about how to fix this?

Thanks.