Toyota Repair: 1996 Camry Overheating, coolant temperature sensor, fuse block

Question
Ted: My son in a college 300 miles away drives a 1996 Camry with 139,000 miles which was overheating. The next morning, he took the car to a Meineke center because that was all that was available on a Saturday morning. They replaced a coolant temperature sensor, because the fan was not kicking on at all. They charged us $69.00 for the sensor and $55.00 for labor. This did not take care of the problem, because he told me the car overheated again whenever he was stuck in traffic. He kept adding coolant after this happened. The problem continued, he took it back to the same Meineke center, and they diagnosed a different sensor problem and charged him another $120. He came home this weekend and I ran the engine for 30 minutes with the AC on. I noticed the temperature gauge rising all the way past the red zone, but no overheating. I also noticed the coolant getting closer and closer to the top. I also noticed the fan never turned on the entire time. When I turned off the car, the coolant overflowed and spilled over. I thought that maybe the tube connecting the coolant to the radiator could be clogged. What do you think the problem is? And should Meineke fix it without charging us?

Answer
I don't know what sensor they replaced it may have been the wrong one, the temp sensor that turns on the fan should be located on the lower part of the radiator, when the engine gets hot the sensor creates an open circuit and the fans are grounded in another circuit and turn on, you can simulate the same condition by disconnecting the sensor, the fans should come on and stay on regardless of temperature, if they do not, check the fuses and the fan relay,they are located in the fuse block under the hood, the fuse is a large 30amp fuse, it is designated something like AM1 or AM2,if this is a V-6 the sensor is located near the thermostat.