87 deville fan light

The check coolant fan light comes on every once and a while. Both fans work but come on when I start the car, is this normal. I thaught about replacing the fan switch but cant find it.

behind the driver side headlight is a control module for the coolant fans,mine was doing the same thing,i went to the local "u pull it" junk yard bought it for $5 and it took care of all the problems. Good Luck !! Greg H