If a cars air conditioner is making you vomit or the air conditioner is making you feel sick then it's likely mold in the vents or the cabin filter.
Your air conditioner in your vehicle contains a cabin air filter that filters the air for the car air conditioner and I myself didn't realize there was a filter for the air conditioner.
That is until I started getting sick to my stomach when the air conditioner was running in my car.
So I told a doctor that every time I got in the car and turned the air conditioner on I would feel sick and want to vomit.
He advised me that it was likely because of mold spores in the cars air conditioner filter and told me I should have it checked out and replaced if it's moldy.
He was right and I removed the cabin air filter for the air conditioner and it was moldy and after replacing it I was no longer getting sick.
The air conditioner itself should not make you sick but there could be mold or other stuff in the air filter or even the air vents that could cause you to become sick.