1997 cherokee country, electric fan only comes on when engine is cold. even a-c override will not get it to come on when hot.
Sound like coolant temperature sensor is open or not working.scan it to see when engine get operating temperature when coolant temperature get 190 degrees the coolant temp sensor should show 190 degrees if it shows 80 degrees or lower it not working replace it.the coolant sensor control coolant fan.when it gets hot it resistance changes or lower.the pcm grounds it .then cooling fans will run.
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fixed problem. fan motor was bad (brushes stuck) motor would not run when it got hot. re-set computer to eliminate fan running when cold. Previous owner had had aftermarket control module for the fuel injection and I think this confused the computer about what temp was actually. everything working perfectly now. Thank you
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