Narrative:

Pilot received a burning smell through the air [ducts]. I advised approach and asked if there were any controlled fires normally for this area. ATC said no and asked if it was my airplane. I replied; I would monitor my airplane and keep a visual for any fires. The smell turned out to be my alternator going bad. A piece which covers; I believe voltage regulator; caused the alternator to go bad. My battery voltage dropped from 14.5 to 12.5. This happened while flying from ZZZ to ZZZ1. I turned off comm 2 and all electric switches; leaving just the bare minimum on to legally land. I eventually diverted to ZZZ2 and called my mechanic from ZZZ1. The alternator was replaced because it was not keeping charge; along with other pieces in the electrical system.

Google
 

Original NASA ASRS Text

Title: Van's RV-7 pilot reported experiencing electrical fumes attributed to a faulty alternator; resulting in an inflight diversion.

Narrative: Pilot received a burning smell through the air [ducts]. I advised Approach and asked if there were any controlled fires normally for this area. ATC said no and asked if it was my airplane. I replied; I would monitor my airplane and keep a visual for any fires. The smell turned out to be my alternator going bad. A piece which covers; I believe voltage regulator; caused the alternator to go bad. My battery voltage dropped from 14.5 to 12.5. This happened while flying from ZZZ to ZZZ1. I turned off Comm 2 and all electric switches; leaving just the bare minimum on to legally land. I eventually diverted to ZZZ2 and called my mechanic from ZZZ1. The alternator was replaced because it was not keeping charge; along with other pieces in the electrical system.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.