This is actually the Low Coolant idiot light. Pop the hood check the coolant level, when designing the level sensor, the engineers screwed up and it throws the light even when the tank is up to the MAX line. Just add your coolant water mixture till the light goes off, making sure there is still some room in the tank for overflow once the fluid is heated.
it looks like a little orange engine in lower left on dash
by licking stuff
http://www.wooddashexperts.com/customer/home.php?cat=2130 lot of dash kits for mercury & ford
cut wire between the dash and radio and fuse box.
The 1999 Mercury Cougar OBD 2 port is under driver side dash left of steering column
The 2000 Mercury Cougar OBD 2 port is under driver side dash next to kick panel
Under the dash on the drivers side of the car.
The 2000 Mercury Cougar OBD 2 port is under driver side dash next to kick panel
The 2000 Mercury Cougar OBD 2 port is under driver side dash next to kick panel
most likely they did not reconnect the fan motor connector - or it cam loose when they replaced the starter - or your fan motor or relay burned out
driver side footwell under dash.
You can view the 1999 Mercury Cougar owners manual online at : www . motorcraft service . com ( no spaces ) Click on Owner Guides