Ambient temp guage ? - 1996 Jeep Grand Cherokee

Check or just replace the coolant temp sensor. This sensor will also tell the computer -40 and stop the a/c if bad connection or faulty part.

Is the engine and compressor running when you connect the hose ?

ambient temp sensor behind grille.

A/C is all conditional upon ambient air temperature. If you are in a high heat area and getting 58 degrees fah., you are doing great. Take it on the highway and see how much further it goes down. The temp. inside is all relative to the outside temp.. That is the science of it. Let me know what your guage readings are and the temp where you are and I can tell you if you are doing good or great.

LOOK ON DASHBOARD AREA FOR A LITTLE BUBBLE LOOKING THING PROTUDING UP SOMETIMES NEAR WINDSHEILD

temp should stay about half while driving sounds like you have a bad thermostat if guage is half way at idle do you have heat feel both heater hoses should be about same temp if one is cooler not flow coolant

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.

Are you talking about the coolant temperature (c/t) or the ambient temperature (outside temp). If you're refering to the ambient temperature the problem is the sensor is located under the radiator support and picks up the temperature off the pavement this is done intentionally to help detect icing conditions and unfortunatley there is no calibration for the sensor.

99% of the time its the thermostat that is stuck open.Does the car s temp guage read normal,if not than change the $10 part.

Right behind the grill around the rad. support on the passenger side (usually) there is a sensor called an ambient temperature sensor. That gives your outside temp. on your rearview mirror.