I would check the coolant temp sensor again and the associated wiring. Also check for the proper reference voltage at the temp sensor connector. As I understand it, when the computer sees the minimum temperature on the ECT sensor (completely open circuit), it compares it with the reading of the IAT sensor at a certain point. If the 2 readings are drastically different, it assumes a failure of the ECT sensor, should set a code, and flips the fans on.

Disconnected the battery over night. Reconnected. Problem gone for today.




However, did find out where my coolant leak was. Think it was the intake mainifold problem that I'm suddenly reading about. Real close to the ECT sensor is a bolt that is leaking coolant.
Called gm service locally and they said it's about 1000 to fix. Any inexpensive workarounds, like bars leak, or tightening the bolt?

Repairing it yourself.

Stop leak may buy you some time, but if you plan on keeping this car for a while, you won't want to bother with it, and should move straight to the repair.

Shop around.......anywhere from 650-1000......

It's a 5-6 hour job, plus parts, oil change and coolant......flat rate guys do it under 5 hours....

Stop leak tends to clog up your cooling system, and should be avoided at all costs. I don't know how mechanically inclined you are, but if you have a basic set of tools there are how-to's on the internet showing how to do this.

Basically not a hard job to do, but at this time of year you need a garage......a novice? Double the time.....and get a manual, or copy pages from one at a dealership.....