Question about 1990 Jeep Cherokee Limited

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1990 jeep cherokee 6cyl inline- electric radiator fan inop.

The electric radiator fan works when I jump the connector to the battery but it isnt coming on at temperature causing the engine to overheat in stop and go traffic when the additional cooling fan is needed. How do I test the coolant temp sensor that screws into the radiator and activates the fan? Does it only have power when the engine is running or will it continue to run after engine off until the coolant temp goes down? Is there a fuse I should check? If so where is it? Thanks.

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  • markoconnell Nov 27, 2008


    s to be a faulty coolant temp sensor not closing at 190 degrees to activate the electric fan. I will replace it and see if fixes the problem.



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The aux fan only works when the ac is on, and has come to a predetermined temp(?) i found this out while going up a long grade in the back country without the ac on and later found out the radiator was half plugged!

Posted on Nov 22, 2008


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98 jeep Cherokee keeps over heating

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If the ECT has air pockets it well never report hot temps.
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page 35 Chapter 7
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I use my scan tool , and innova 3140 for jeep OBD1.
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