There are quite a few modern cars with sprags on the alternator pulley. From what I've seen and experienced (with factory bulletins outlining the reasons), they're almost always installed to keep the belt from chirping or wearing out prematurely. On the rare instances when I'd see a failure of the sprag (almost always would fail locked up in both directions), the telltale symptom was a loud chirping noise on shut-down or start-up or a shredded serpentine belt, with a pile of belt dust/felt/hair all over the engine compartment.

IMHO, the only reason for this exercise is to reduce the inertia from the alternator rotor from affecting the fan during decel., shifting, etc. However, without driving the fan, airflow would be minimal/nil. Disconnect power from a desk fan to replicate.

Separate the alternator from the fan and you might have more control over those individual components. Recapture some high rpm power by momentarily stopping current generation.

Disregard the flat fan. Same dif.
http://forums.pelicanparts.com/uploa...1570475132.jpg

Sherwood

Yo Playa! I want to get this to match my spinning wheels when i come to a stop!