I filled up my window washing fluid tank and the light inside remains on? what the heck?

The sensor is bad or maybe a bad connection.

Most likely a bad sensor.

inexpensive? easy to replace? where is it located?
thanks alot

Not to bad to replace it is mounted in the coolant bottle.
I think the sensor might be like $50.00 or so.

Does it HAVE to be a 98 S90 sensor? or are all volvo window washing fluid sensors universal? thanks

Not 100% sure you have to make sure the plug is the same.