the low coolant light came on yesterday, but the coolant is full. on 1999 Chevrolet Venture

could it be a frozen thermostst?

Asked by for the 1999 Chevrolet Venture
Located in coolant recovery tank.
1 more answer , 1 more comment
most likely a coolant level sensor
where would the sensor be located, or how much to repair, i bought this van and its beating my wallet up.