external temperature sensor does not reflect correct temp
The external temp sensor affects the operation of the HVAC system. For example, if the temp reading is less than ~38*F, the AC will not be allowed to turn on. In fact, even if you set the HVAC to the coolest setting of 60*F, the system will not blow cold air (only fresh outside air) since the AC is disabled. Your sensor is likely bad or the connector has corroded affecting the impedance of the circuit.
To temporarily fix your problem, unplug the sensor and the temp will default to ~ 58*F, which will allow your AC to operate. The sensor is located under the nose of the car on the passenger side of the radiator cavity just above the air dam. You can reach it by raising the hood and reaching down between the frame rail and the rad cavity - just unplug the connector.
The sensor itself is only about $12. You may need to also check the connector for corrosion to may sure it's not part of the problem. You HVAC is probably fine.








