When driving in a warm rain, the windshield fogged up. I turned the defroster on to quickly defog the windshield, the blowing air started slightly warm then turned cold. I kept turning the temp up, only to have it turn cold again. I tried the defogger, only to have the same problem. I had to run the defroster on the max hot setting to keep the windshield defogged. It was summer, so max hot air blowing meant extreme sweating while driving just to keep the windshield clear. Took the car to the dealership service dept. After a diagnostic check, they said nothing is wrong with the car.
Update from Nov 19, 2015: One week later had the car into the service dept. for the same problem. Servicer manager saw and acknowledged the problem, but it does not show an error code on their computer, so they cannot do anything for me.
Update from Nov 19, 2015: Once again had the car into the service department. The technician stated a defroster should not work this way, but it is the way the system was designed. Although the owners manual states that turning on the defroster deactivates the auto climate function, on these vehicles the auto climate still operates the defroster, and will change the warm air to cold air on its own. The only way to blow consistently warm air to the windshield is to set the temperature to max hot. Which means over 90 degree air blowing into the vehicle. I have to constantly turn the defroster/defogger on and off to keep the windshield clear, as 90 degree air consistently blowing out is overwhelming to say the least. I talked to 2 other GM service departments, who stated many complaints have come to them with this same problem.
Update from May 17, 2016: Car now has 4000 miles on it. Defroster will blow warm air only if the defroster is the first climate setting chosen. If we use heat, vent, A/C first, then try to use the defroster, only cool air will blow from defroster. Warm air will blow from all other settings, but push defroster, cool air comes back. Took car to another dealer service dept., no codes are showing up, so nothing they can do. Cool air will not clear fog from a windshield, it makes it worse.
When driving in a warm rain, the windshield fogged up. I turned the defroster on to quickly defog the windshield, the blowing air started slightly warm then turned cold. I kept turning the temp up, only to have it turn cold again. I tried the defogger, only to have the same problem. I had to run the defroster on the max hot setting to keep the windshield defogged. It was summer, so max hot air blowing meant extreme sweating while driving just to keep the windshield clear. Took the car to the dealership service dept. After a diagnostic check, they said nothing is wrong with the car.
Update from Nov 19, 2015: One week later had the car into the service dept. for the same problem. Servicer manager saw and acknowledged the problem, but it does not show an error code on their computer, so they cannot do anything for me.
Update from Nov 19, 2015: Once again had the car into the service department. The technician stated a defroster should not work this way, but it is the way the system was designed. Although the owners manual states that turning on the defroster deactivates the auto climate function, on these vehicles the auto climate still operates the defroster, and will change the warm air to cold air on its own. The only way to blow consistently warm air to the windshield is to set the temperature to max hot. Which means over 90 degree air blowing into the vehicle. I have to constantly turn the defroster/defogger on and off to keep the windshield clear, as 90 degree air consistently blowing out is overwhelming to say the least. I talked to 2 other GM service departments, who stated many complaints have come to them with this same problem.
Update from May 17, 2016: Car now has 4000 miles on it. Defroster will blow warm air only if the defroster is the first climate setting chosen. If we use heat, vent, A/C first, then try to use the defroster, only cool air will blow from defroster. Warm air will blow from all other settings, but push defroster, cool air comes back. Took car to another dealer service dept., no codes are showing up, so nothing they can do. Cool air will not clear fog from a windshield, it makes it worse.
- katacom, Portage, IN, US