Quote:
Originally Posted by yal
Arthur shouldn't he jumper the connector for the blue switch to get the aux fan to kick in? Does it work like the red switch for the big fan? Just curious, is it a different type of switch?
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No..........b/c it is not a switch..it is a Negetive Coeficient Thermister..which is just tech lingo for a resistor that changes value with temp change.
So, if the CC sees a high resistance value in this sensor , it does not trigger the fan circuit..but if it sees an OPEN circuit [ as in unplugged] , the CC defaults to FAN ON automatically. [ High temp protection in case of sensor/wiring fault] That is why we use the unplug sensor test to check the high fan circuit..we are simply putting the CC into DEFAULT funtion..simplest test there is for high fan circuit integrity..if that test fails , we start looking at fuses/relay/ resistor/etc..but we START right there w/that sensor....
If it were a regular temp sensor , [mechanical type sw ] you would then have to jumper it to turn on the fan.
This type circuit is just the opposite. It triggers a transistor in the CC at 285 ohms [ which eguates to 105C ] OR open circuit.