Hey guy ! My 850 coolant fan just refuse switch on when the reach working temp. on 1995 Volvo 850

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I have check fuse (good) ,Swap out the fan relay with another (No change).Q? can it be a defective ECT sensor.Can this cause the fan not to switch ?
(2) Answers
You will need to diagnose this properly by checking to see if you are getting power to the fan when the engine is warmed up. I do not suggest replacing any more parts until you do this. You can do this with a test light or a voltmeter.
If you are not familiar with how to perform an electrical diagnosis of a circuit, then I suggest taking it to a shop.
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