electric fan/generator!
Yes,its true!--I've seen the same thing on my friends 82 cutlass--he added an electric fan and he must have tapped into the big pink HEI 12v wire to get a "switched hot wire" from the key...his car would keep right on running for about 5-10 seconds after you shut the key off!--
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-He added a diode to the power wire(I told him sometimes you need a diode on a GM altenator when you swap one onto something that never had one originally,like a farm tractor for instance,or the same thing happens,it wont shut off with the key!)--that cured the "run on" problem--but he should have wired it right as suggested already with a relay and a separate power source.(and fuse
)...his car always had a weird skip no matter what motor he had in it(he had 5 different small block chevy's in it over the few years he owned it)--I wonder if the fan being "piggybacked" onto the HEI power wire reduced the amps and volts enough to make it run that way..
Also makes me wonder if your electric fan helps charge the battery when your going down the highway and the wind makes the fan motor run faster than it normally does,making it into a generator--I know the fan motor DOES act as one,the fact it keeps the car running those few seconds proves it!--I've chucked an old fan motor from a K-car I replaced in my drill press,and spun it at a good speed(2500 rpm or so)and it will light up a 1157 bulb pretty good, if you hook it to the power and ground wires!..
It does not put out very much amperage,maybe 1 amp..but I guess any fan or heater motors like those with permanent magnets also can be generators as well-(like the ones on our bikes as kids!)-I was tempted to use one on a riding mower I added on electric start to from a parts engine, to charge the battery--havent had enough time to play with it,but I bet it would work--and would not bog down the motor as much as a regular GM altenator.
.One flea market vendor I've seen has been selling "windmills" made from car electric fans that light up a bulb at night pretty good in a stiff wind!..he sells quite a few!.one was a fake "lighthouse"!.I thought it was a cool idea...
--I'm also wanting to put a GM altenator on a 5HP engine so I can use it to boost dead batteries( got lots of dead ones from lack of use due to gas prices!
) or as a remote 12V/110V power source,using an inverter--they are pretty cheap now for a 400W one--be nice to run a drill or saw away from the house...or for camping...
