I have a 1999 Grand Am SE V6. I just recently purchased it. It was running hot so I had the thermostat, water pump, the pressure cap on the reservoir tank and flushed the radiator. Come to find out my fans were not working. I researched and found out the thermostat coolant sensor was bad. I had that replaced as well and the fans work now. BUT now that all of that has been done the temp. gauge on the dash does not work! I was told there is another sensor that controls it. Does anyone know anything about that? I have checked fuses etc. and I am stumpped. Any sugestions would be appreciated.

Welcome to AF!

Thier are several mini relays and fuses in the cooling system.
First Id check the plug in and wires to the temp sensor located below the throtle body-TB.
Might also check out this thread if you hadnt already.
Coolant Temp Sensor on 99+ Grand Am Testing (http://www.automotiveforums.com/vbulletin/showthread.php?t=660655)

Hope that helps!

so you replaced etc very good, but you did not connect it :) that is why your fan is working now because pcm sees open. Make sure that the two wire connector as "XI" stated is connected to your ect sensor.

you probably have problems to start when hot