[urq] alternator whine - SOURCE determined!!

[Ado Sigal]

Brandon Rogers wrote:

>Guys-
>We have made progress. A few people mentioned this possibility.  Drum
>roll please.....
> 
>Alternator fan.  Creating a siren effect.
>
>  
>
Nice to hear that Brandon; suggested so some time back, no? If its doing 
it in static conditions, and only when on your car, it means that 
something close to the fan is interacting with it. Send some pics and I 
let you know. Work on the fan itself however, you should do regardless. 
Bit tedious, but it quiets the fan to a minimum noise. It involves 
rounding all the square edges of the fan with fine cut file.  Those 
edges that cut the air vertically (inner and outer) should be 
symmetrically rounded, and those that cut horizontally should have fine 
teardrop shape (symmetrical chopper blade profile). Better finish 
relates to less noise, and by hand could take god couple of hours, and 
if accompanied with 6 pack, you'll end up singing.

Cheers,

Ado