Does 02 sentra have ambient air temp sensor? if yes, where?

Supposedly blinking ac indicates ambient air sensor needs replaced ?????? no it doesn't ! Why don't you do yourself a favor an take it to a qualified repair shop that knows how to diagnose it correctly . Hooking up a factory or professional scan tool an checking for code's is the first thing to do. The way to know if a sensor has a malfunction is by A stored DTC - diagnostic trouble code .
DTC Descriptors
DTC B0158 02: Outside Air Temperature Sensor Circuit Short to Ground
DTC B0158 05: Outside Air Temperature Sensor Circuit Short to Battery or Open
DTC B0163 02: Passenger Compartment Temp Sensor 1 Circuit Short to Ground
DTC B0163 05: Passenger Compartment Temp Sensor 1 Circuit Short to Battery or Open
DTC B0168 02: Passenger Compartment Temp Sensor 2 Circuit Short to Ground
DTC B0168 05: Passenger Compartment Temp Sensor 2 Circuit Short to Battery or Open
DTC B0173 02: Output Air Temperature Sensor 1 Circuit Short to Ground
DTC B0173 05: Output Air Temperature Sensor 1 Circuit Short to Battery or Open
DTC B0178 02: Output Air Temperature Sensor 2 Circuit Short to Ground
DTC B0178 05: Output Air Temperature Sensor 2 Circuit Short to Battery or Open
DTC B0509 02: Output Air Temperature Sensor 3 Circuit Short to Ground
DTC B0509 05: Output Air Temperature Sensor 3 Circuit Short to Battery or Open
DTC B0514 02: Output Air Temperature Sensor 4 Circuit Short to Ground
DTC B0514 05: Output Air Temperature Sensor 4 Circuit Short to Battery or Open
DTC B3578 02: Output Air Temperature Sensor 6 Circuit Short to Ground
DTC B3578 05: Output Air Temperature Sensor 6 Circuit Short to Battery or Open
DTC B3583 02: Output Air Temperature Sensor 7 Circuit Short to Ground
DTC B3583 05: Output Air Temperature Sensor 7 Circuit Short to Battery or Open

ambient air temp sensor is same as intake air temp sensor. IAT Sensor on this vehicle is located in the intake air duct between filter and throttle body.

The outside temp sensor is located behind your front grille. Try to look for a 2-wire small sensor. You will need to remove the grille to gain smooth access and to test it. Use multimeter to measure sensor resistance when disconnected. Depending on actual air temperatures, sensor should measure 1.27 kilohms when at 104degF, and 16.5kilohms when at -4degF. The rest of the normal values should be in between these kilohms and temperature ranges.

code p 0072 refers to outside air temp sensor ( ambient temp sensor--low input===causes ---wiring short to ground, outside air temp sensor ---ECM
thee has to be an ambient temp sensor as that reports the temp to the ECM to adjust the air/fuel settings for cold starts
it could be in the MAF/VAF sensor area

run the fault codes
indicates a problem ambient temp sensor or a Baro sensor that is not report correctly to the ECM so the correct cold start air/fuel mixture is not being set

Yes it could be the sensor is cheap and it is located in front of the AC condensor core which is front of the radiator..

The ambient air temp sensor is located on the radiator support bracket at the top (see figure below, item 1)

Hi ruswashingto,

The air conditioner may not work properly if your ambient temp is reading -40. The a/c control unit monitors ambient temp so that it does not operate at too low outside temps. I would recommend fixing the ambient temp sensor and rechecking your a/c operation.

most ambient air sensors for your inside temp display are in the grille area behind the grille the only other temp sensor for ambient air temp is in the intake duct for the engine.

there is an ambient temp. sensor in the intake air ducting, if its a small round two wire plug you can unplug it and the computer will think its -40C. You will set a code when you do this, but should go away after you plug it back in.
Depending on the engine you could have a cracked mainshaft in your distributor which is quite common, unfortunately most cracks are on the underside of the shaft which requires removing the distributor.