Have a 1998 lincoln town car cartier edition. About 100,000 miles. It has been overheating a couple of times. Had the thermostat replaced. The air conditionor compressor started smoking. Had it replaced and system charged. Over heated again. The temperature gauge is not going over half way up. Checked the fan, not coming on. Ran hot wire to fan, fan motor is ok. Bought an engine coolant temperature sensor, can not find where it goes into engine? It is not by the thermostat neck. Looked under, right side, left side of engine. See what looks like it, in the center of the engine on top into the head, dealor said that was the engine head temp sensor, not the coolant sensor. Need some help and some ideas of what to do. Does this 4.6 liter engine even have a coolant sensor?