After replacing my radiator and starting the car to flush out the old bars leak all my dashboard lights are on, and stay on. Don't know what to do next.

 

Did you unplug the battery, or the ECM?

 

I've had the battery - both cables - disconnected for a few months while the car's been sitting in my garage. Why does that matter? Except that I know this means no codes will be visible. Should I reconnect the cables and leave them on?

 

I'm now keeping the battery connected. Idled the car for about 10 minutes earlier. The dashboard lights, most of them anyway are just staying on while the car's on. The temp gauge went to a drop above 3 o'clock and the fan never came on. The heat works but not with the fan on auto, only with the slider moved to the right side for setting fan speed.