General Maintenance & Repairs - Condensation on AC when not in use...

I was driving home from the track Friday night (about an hour drive) and when I finally get home I pull it into the garage and hear something dripping onto my longtubes. I fear the worst, grab a flashlight and start searching. I finally look under the car on the passenger side and see a puddle of water, and notice the water sizzling and dripping off of the header. Open the hood, realize there is condensation on my AC compressor. I never once turned on my AC during the drive, but did have my heat on low when I got closer to my house near the lake. Is this normal? I don't see why the AC compressor would have condensation on it unless it is for some reason always running, in which case that would explain why I can't get above 20mpg no matter how hard I try. If there is no way around this and this is normal operation, I am thinking about just pulling my AC since I rarely use it and would rather save the power/gas. Let me know what you think.

Is the clutch on the compressor turning on and off ? You might want to get a buddy, start the car and get under the pass side and have the buddy turn the A/C on and off and see if the center of the compressor is turning on and off. It sounds to me like the compressor is running all the time.

I finally look under the car on the passenger side and see a puddle of water, and notice the water sizzling and dripping

Perfectly normal and happens to every car with air conditioning. The more humid the air, the more condensation you'll get.


I never once turned on my AC during the drive, but did have my heat on low when I got closer to my house near the lake. Is this normal? I don't see why the AC compressor would have condensation on it unless it is for some reason always running, in which case that would explain why I can't get above 20mpg no matter how hard I try.

You probably turned on the A/C but didn't know it. The A/C runs as a key part of the front window defogger system. So, if you turned on the heat along with the defogger setting, the A/C will kick on.

If the A/C is kicking on in the floor heat setting, then you may have an issue with the switch at the console, but I'd say this kind of thing would be highly unlikely.

I vote a defrost option was selected.