One problem related to alternator/generator/regulator has been reported for the 2005 Chevrolet Cobalt. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Chevrolet Cobalt based on all problems reported for the 2005 Cobalt.
My car shut off while driving out of a parking lot a couple of days ago. Everything shut down. I couldn't even brake. I was able to put the gear in park and restart it just fine. However this is the fourth time this has happened. The last time being on the george washington bridge. The very first time was 2 months after I purchased this car. I assumed it was because I went over a speed bump that was larger than normal. The second time I went over a pothole. The third time was on the highway. So I had a mechanic look at it and he stated that I could be the alternator. This was about 2-3yrs after purchase. However my time was very limited. I live in MD but I work in new york so I spend a lot of time there and leave my car at home. So I haven't had a chance to get it fixed. With this last incident I decided to search the internet and it turns out that I am not the only one with this issue. I found it funny that there were many others with the same or similar problem. I put in a search for "cobalt shutting off while driving" and found a couple of sites describing similar issues. This last incident reminded me of how dangerous this could be. I had my 4 yr old niece in the backseat and the exit of the parking lot was on a hill. Feeling the car rolling back and not being able to brake would surely be considered a safety issue. On a side note I did have my car examined for the recall I was given notice about. This was completed last year. Nothing abnormal was reported.