I have a 2013 Chevy Cruze and all of a sudden I get in the car and there is no A/C. The fan is blowing just warm/hot air. After checking the fuses (not sure how to test relays) I did notice that while the hood was up and the A/C button was engaged that the radiator fan was not coming on. I let it sit for a little bit in around mid 90s outside weather and the fan never engaged. I decided to drive it around for a little bit and pull over to see if the fan was engaged. From what I've seen it has never engaged. I drove the car today on the interstate and the A/C still would not come on. I read some from googling the issue and some people report that the A/C will work at highway speeds but not lower. Mine doesn't work at all and I'm not exactly sure what else I can check myself. Also, related would be the engine temp doesn't appear to be overheating at all. This is normally my wife's car and for the past couple of years she said that the A/C hasn't worked for a week or two during around the changeover from summer to fall, I'm not sure if this has anything to do with anything or is a weird coincidence. Any suggestions would be appreciated!
The first thing I would check is to see if the air conditioning compressor clutch is engaging when the system is on. The fan probably won't come on if the AC compressor isn't engaging.
Does the fan engage when the car sits at an idle in the driveway? After it comes fully up to temperature, the fan should start. The threshold coolant temperature is typically fairly high; on one of my cars it is nearly 220F before the fan kicks on, so on a very cold day it might never get there. Much of the time, the airflow through the engine compartment caused by driving the car down the road suffices to cool the radiator off and the fan doesn't come on, unless the load of the A/C is being applied as well.
If the A/C compressor doesn't engage, the likely cause is that you have a refrigerant leak, and the system needs to be recharged. Ask for the technician to put in a leak detector dye and then use his sniffer tool to try to determine the cause of the leak. It may be a relatively inexpensive repair; there are o-ring seals between the components that can wear and trigger a leak. Worst case scenario is a leak in the evaporator under the dash; these are expensive to repair because it is time consuming to remove and replace the dashboard. It would not be unusual for such a repair to cost the equivalent of US$1,500. A recharge/leak detect/dye should cost you less than US$200; any leaks found will vary in price to repair.
First thing i'd do, would be to stop trying to engage the AC system/defroster and take the car to a good shop and have the refrigerant charge weight (not pressure) assessed as soon as possible.
If a correct or not terribly low charge is found, then it's likely an electrical problem with faulty sensors, a faulty compressor clutch or faulty wiring (for example, my car had a faulty AC clutch connector and the compressor clutch suddenly stopped engaging; found out by giving a good yank to the AC clutch wire and then discovering the compressor clutch actually engaged, until the car was driven over rough roads, and knew the refrigerant level was perfect, because i didn't hear any refrigerant flow sounds when putting an ear right under the expansion valve under the dashboard).
If a very low charge level is found (for example 50 grams of refrigerant out of 500), then you definitely have a serious leak.