So on this and a recent hot trip of more than one hour my air conditioner shut down while driving. On both occasions I heard a click and immediately the air conditioning and blower fan shut down. Both times I have been able to restart ac by stopping, shutting off the truck, and restarting it. Then drive with no further problems. Both times cooling was set on high cool but not max and fan was on two or three so not on high. Mine is 2017 XLT 3.5eb and I have extended warranty so will probably take to my dealer when I return home. Anyone have similar problem and what was the solution?

 

Probably low on refrigerant and the evaporator froze up. Stopping gives it enough time to melt enough for air flow to be restored and it turns back on.

 

Evaporators cannot freeze up unless there is a failed evap sensor.. There is a temperature sensor on the evaporator and the computer will not allow it to go below 33 degrees. Once it reaches that point it cycles the compressor off. This replaced the old cycling switch. On variable displacement compressors the computer reduces compressor output. Also, if it was low on refrigerant the computer would detect low pressure and won't allow the compressor to run for more than a few seconds.

 

That takes time to melt, it wouldn't restart operations with a simple stop, power off, and power back up. An unlikely scenario.

Since the blower also shut down, it's not an issue solely with the compressor or its control electronics. It has to be "upstream".

OP: Need to tell us if it was an auto or manual climate control system. Any other symptoms when the climate control went offline?

 

Thank you. it’s a manual control climate system. Both times I was recirculating air, fan speed on 3 or 2, once in 95* humid MO and then in 85* WI, both times while driving at 70-73 mph w/std cruise control in operation.

 

Any sense of where the clicking noise may have originated from?

 

A scan for DTCs using FORScan or diagnostic scan tool should be performed. The FCIM can issue a variety of DTCs related to the HVAC system. Simple code readers usually only read DTCs from the PCM/ECM. I suspect the issue is with the FCIM or Blower Control Module since the blower stops working and then works again after an ignition cycle.

 

I’ll conduct FORScan read when I get home. Thanks

 

No DTC. Dropped off at dealer, was 5% low on refrigerant and we’re doing the dye test.

 

Freezing up 95% of the time means low refrigerant.