ClydeFrog

Was driving around in the hot 90s here in the Midwest & started having an odd AC issue. Was moving along around 65-70 & all of a sudden the AC starts blowing hot air. AC shows on & no matter what I did, changing modes, vents etc, turning AC on & off nothing changed the air temp. Pulled over to check the compressor, everything looked ok. Turned the car off & back on - Ice cold air. Parked, then started the car for the trip home & the air temp was barely cool, had to turn the fan way up & the temp way down to keep the car comfortable. Stopped for gas & started the car up - Ice cold air again. Engine temps were fine, rock steady at 210. Doesn't seem like a charging or compressor issue, more like a sensor or programming. Car was just recently tuned a couple of days ago but doubt that had anything to do with it. Anyone else ever have these issues or any insight?

rrsperry

Was the system in Auto?

ClydeFrog

I use both modes. I'll set it in auto & then manually change the fan speed as needed. It was in auto both times it went nutty. Switching it out of auto & turning AC on & off did nothing either time. Only turning the car off seemed to fix the issue.

c54u

How old is the battery in the car? Did you get a chance to see what the voltage was when the A/C stopped blowing cold air? Battery may be on the way out and maybe internal programming sacrifices non essential drain on battery to preserve voltage. Just a wild guess. I would do a load test on the battery.

Did you get a chance to note the outside temperature on the infotainment system and was it accurate, because that sensor is used in conjunction with your HVAC system. I had one replaced on my Buick and HVAC returned to normal operation after the sensor was replaced.

Or the tune has something to do with the problem.

Just tossing ideas out.

ClydeFrog

The car is only 3 months old so I don't think its a battery issue. The OAT seems pretty much spot on with no off or erratic temps.

I've seen the threads where people had issues cooling their cabin. I'm not having that problem. It's more like a roulette wheel of what air temp I'm going to get when I start the car.

It's going back on the dyno Thursday so I'll ask about the tune then.

Thanks for the input.

ClydeFrog

Did it again on the way to work today except this time the passenger side was cold & driver's side was warm in sync mode. Figured it was a mix door going screwy. Pulled & pushed the HVAC control (17) fuse & ran the temp full cold to hot a few times in service mode. Fan flow changes & thuds from the vents confirmed the doors operating in unison. Four car starts now & the AC is ice cold on both sides. Hope this helps someone in the future.

jcthorne

I have been continuously amazed at how poorly the auto climate control works in a $100k vette compared to my 17 year old Ford Excursion.

bbrown450

Had a 14’ for 4ok miles ...you have better odds in Vegas !! While I am sure many out there extoll the virtues of their c7’s System, thats great, I am going on 60+ k with what I have on the odo for my 16’ and I have given up on trying as the dealer says operates as it should. I clocked the temp in my driver footwell at 112 degrees. One of those things I never could understand given the performance otherwise.

Red C8 of Jax

I have a 2015 and since new my AC has had a mind of its own. It has never blown hot air but one day 70 degrees is cool and the next day 70 degrees is ice cold. Some days I have to adjust the controls to low to get cold air and other days 72 will freeze you out. As long as I can have cold air I will keep my car away from the dealer. I will only take my car to a dealer when it is my last resort.

iclick

Same here comparing it to my $18k Frontier truck. I attribute it to much higher exposure to sun with much larger glass surfaces causing the sun to beat down on more interior areas. My C6 and first C7 were the same way and adequate for me. They could engineer a higher-capacity unit, but it would take its toll in mileage and performance. I wonder how it performs compared to its competition in the sports car arena.

SD_Dave

It looks like something is wrong with the Auto mode in the AC. I have a '16 Stingray and in auto AC the temps were all over the place.

I read about this in some other thread and followed their advice. What I now do is set the temp between 67 and 72 deg with the auto off. I control the cooling effect by changing the fan speed only. This has made a world of difference for me. I live in So Cal and using this method the car stays nice and cool. The system capacity seems fine.

Jaykoh-Z51

I noticed my cool air will temporarily stop when the engine gets loaded. Say, I didn't give enough gas (M7) when a low gear and the engine lugs a bit.

Aaaaaand sometimes it doesn't. A little screwy. But never acts up at steady RPMs with steady speed.