I have a 99 Grand cherokee with a 4.0 Straight 6 and the fan refuses to come on. I have verified the fan itself by applying direct power and its fine, i switched the relay in the box by the battery and the fuse in the same box is good. The only temp sensor i can find in the book is the one in the thermostat housing for the temp guage and it is showing accurate temps as verified with a thermometer.
Is there a sensor i am missing or could this be a computer problem? Any ideas will help i'm stumped and i really dont want to put a manual control on the fan. Is thier a test i can perform to check the cooling circuit? Maybe applying a specific voltage to the sensor wire?
tia... Mark