In a message dated 8/10/2003 1:11:49 PM Eastern Daylight Time,
twjames@healed.org writes:

> What do those with "Fan" experience say about preventing this kind of
>  problem?
>  Will a diode in the right place prevent these little dynamos from blowing
>  fuses and disrupting the engine?
>  Lynn, How would you do in a race car?
>  
    Use a double throw double pole switch. Connect both fan wires to the
center,
    (switchable) connections. Connect the power wires to one end connections
and to
    the other end connect a jumper, shorting the two terminals. In the "OFF"
position.
    The wires from the fan are shunted, and the fan will not spin up to any
extent until
    you turn it on.

    After you look at that for a while, you will notice that you can use a
single pole
    double throw switch, and switch only the powered side and let aircraft
ground do  
     the other side. I would do that, but, I would use the double switch and
strap the
    terminals into pairs. Then the contactor area is doubled, and the switch
will last
    longer.

     Lynn E. Hanover