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Discussion Starter #1 (Edited)
Please advise what should be the correct resistance reading when checking the hi/low resistor for the radiator fan

2011 dodge grand caravan


i know that it should not reading OPEN
Can anyone please check the resistor across the Resistor on a newer, working correctly late model radiator cooling fan resistor deenergized power off please. thank you
 

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It's a thermistor (variable resistor) which has a negative temperature coefficient. So the resistance drops as temperature increases. There is no one value.

For reference, other cars generally run about 1000 ohms around 70F, and about 600 ohms near 190F or so. When cold, around 30F, they can measure around 13K ohms to 15K ohms. The resistance declines rapidly as it heats up.

If you are measuring open, first check your meter and leads - cross the leads and you should get zero or very near zero ohms. If you don't, your measuring device is faulty. If you do get zero ohms, make sure both leads are actually in contact with the thermistor leads. If you are reaching blindly into a connector housing, you may not be making contact with one or both pins.
 

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Discussion Starter #3
It's a thermistor (variable resistor) which has a negative temperature coefficient. So the resistance drops as temperature increases. There is no one value.

For reference, other cars generally run about 1000 ohms around 70F, and about 600 ohms near 190F or so. When cold, around 30F, they can measure around 13K ohms to 15K ohms. The resistance declines rapidly as it heats up.

If you are measuring open, first check your meter and leads - cross the leads and you should get zero or very near zero ohms. If you don't, your measuring device is faulty. If you do get zero ohms, make sure both leads are actually in contact with the thermistor leads. If you are reaching blindly into a connector housing, you may not be making contact with one or both pins.
Thank you for responding. well, for the one installed on the aftermarket fan, it read OL, thank God I had the old fan i remove the thermistor and checked it woth outdoor temp around 75 degreess, it read 0. i put it on and now fan works again. Idk why the fan thermistor failed that was on there though.
 
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