I would start with the temperature sending unit. It can cause both of these things to happen. First, it sends a signal to the computer which then tells the cooling fan to come on when a certain temp is reached. It also sends the signal to the temp gauge in the car. If it is shorted, it may be the problem.
Let me know if this helps or if you have other questions.
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Monday, December 21st, 2009 AT 10:58 PM