The fan worked when the AC was on but otherwise it failed to work. I replaced the grey temp sensor. Fan worked. While I was at it I replaced the thermostat because I had to remove the housing to get the gray sensor out. I tested the car and it ran great with good temps and the fan worked without the AC on. This was yesterday. Today I drove the car and all was well. I made several short trips with short stops. I came home with no issues. I left again 20 minutes later and got 10 minutes down the road and I was overheating. The fan is now not coming on even if the AC is ON. The temp just creeps up until it's overheating. The car cools fine at interstate speeds. The fuses under the hod drivers side look fine. I have to drive about 70 miles tomorrow. I'm considering hot wiring the fan to the battery. I really didn't want to cut into the harness. Side note, while the car was running moment ago and getting quite hot, I pulled the plug off the grey sensor and the engine seemed to rev up a bit. It was quite odd. I didn't confirm by looking at the Tach. When I plugged it back in, it idled down. It wasn't as if someone was flooring it, just a little more gas. Seems like the sensor is having some affect on the computer, but the fan just isn't cooperating. I never confirmed the old sensor was indeed bad. I'm not sure how to test it other then put an ohm meter on it and drop it in boiling water. When I did the sensor swap my battery light came on. I let the car run for about an hour or more and the light went off so I figured the batt was a bit low. I just want to be thorough in describing all possibly related symptoms. Thanks for the help.
Fan not working on 1997 Ford Thunderbird
by proaudioguy in Deltona, FL on November 29, 2012
ANSWER by globalhelper , November 29, 2012
could be a number of issues. is the coolant full,it will do this if there is low coolant. could be cooling fan relay or stuck thermostat. did u put the thermostat in the right way? sorry had to ask