My sister has a 1995 Chevy Lumina with the 3.1 liter engine. Her car tends to overheat at idle; we have determined that the radiator cooling fan does not kick on.
In our efforts to diagnose the problem, one possible solution appear to be a faulty ECT sensor. However, the dash gauge does work (that is how she determined it was overheating in the first place); as such, I am curious if this render a problem with the ECT sensor unlikely? That is, is the ECT sensor responsible for sending information to both the dashboard gauge and the coolant fans, or just the coolant fans? If the ECT sensor only controls the cooling fans, how does the vehicle monitor operating temperatures and send this data to the dashboard gauge?