[alfa] Fan switch issue

["Ed & Marsha Prytherch" <mred2u@xxxxxxxxxxxxxx>]

It sounds like a bad switch. Connect a voltmeter across the switch
connections when it is cycling. If the voltage swings from 0 to 12 volts as
the fan turns On and OFF then you have a bad switch that is chattering. If
it stays on 0 when the fan stops then you have an intermittent open circuit.
If it stays on 12 volts then you have an intermittent short.
Ed Prytherch, Columbia SC
73 GTV
79 Spider

George wrote
>Here's a strange one. On my GTV-6 even with a new thermal fan switch
installed, the fan cycles on-and-off so quickly that the engine runs
very hot. With the thermal switch bypassed by a jumper, so that the fan
runs all the time, the engine remains cool. There is nothing in the
circuit but the fan relay and the switch, but the relay is in use
whether the thermal switch is in the circuit or a jumper is in it's
place. Why would the thermal switch make the fan cycle on and off (it
only stays on for about 10 seconds before it cuts off, then it starts
up again as soon as the blades stop turning and runs for another 10
seconds) even when the temperature gauge on the dashboard says that the
engine is so warm, the fan should be running constantly? BTW, the
radiator and water pump are both new as of a little over 5000 miles
ago, the cooling system's been bled, two thermal switches have done
exactly the same thing, and the problem started out of the blue after I
had the engine cleaned a little over a week ago.  I've got to say, I'm
puzzled with this one. Any suggestions will be greatly appreciated
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