Oldsmobile/Buick Repair: 96 Riviera, cooling fans do..., sensor water, temperature switch

Question
96 Riviera, cooling fans do not kick in except when the coolant sensor is disconnected then it runs continuously. Have changed thermostat, coolant sensor, water pump, checked all underdash fuses and relays I could find. AC compressor doesn't engage. I give up and need advice.
Thanks
Brett  

Answer
Your most likely fault is the TEMPERATURE SWITCH which monitors engine temperature an turns on the fan at approx 220-240 degrees.

Autozone has one listed as a WELLS # TU178 for $17.00. This is a singlw GREEN wire connector on the sender. This is also known as a COOLANT SENDER not a COOLANT SENSOR. It is located usually near the alternator and is hidden very well, So look hard. If you want to test it. Simply unhook the single green wire and ground it to the engine with the ignition ON and the fan should run.