[hans2]

The Alfa Technical Service Bulletin manual has a page reminding people of how to avoid damaging the alternator. Included are things most of us already know, such as not to disconnect the battery or alternator cable from a running engine. But I was surprised to read the warning about using timing lights connected to the vehicle's power supply. In fact, the owner's manual stipulates to connect timing lights only to another 12V source.

Why would use of a timing light pose a risk to the alternator or voltage regulator?

 

[Dragline]

Have questioned this myself recently. I see no reason and am a loss as to the possible problem. Certainly interested to see if someone comes up with a good one.