97 aerostar heats up

driving to town the other day when van overheated on me, noticed that heater hose tee was cracked and leaking. Replaced tee but gauge was still going past the red line. Drove back home and started smoking inside the cabin pulled over and let it cool down. Went to autozone today to test it, the guy tells me that the circuit is low in the coolant temperature sensor and to check the wires. Where is the coolant temperature sensor and is this the problem

do NOT drive while overheating, guarenteed engine failure, may have damaged engine or transmission already.
i suspect a failed thermostat
recommend taking to mechanic for complete cooling system inspection.

My van started heating as well, I was coming back home from the U.S., I was about 200 miles away from home and it was at night, I had tools and silicone, so I took the thermostat off, an old man gave me water so I kept going, It kept on overheating everynow and then, It took me home, next morning I took it to the mechanic, he told me it was the fan clutch. I put it brand new, before testing it local, I went to Phoenix, before crossing the border through Agua Prieta it overheated again, I took the thermostat off again and when I got to Phoenix, my uncle suggested to change waterpump, even though, the mechanic had said it couln't be water pump because it was not leaking, When I took out I was surprised it was still working, it was missing that little thing inside, "aspas"in spanish, so you might want to check water pump. (if any mistakes it's because I learned my english in Mexico.) Aerostar 96