My battery light came on steady today, so at the advice of my father I cleaned off the contacts, filled the water in the battery, went for a drive to get the charge back up and when I got home all my interior lights were dimming, below a certain RPM (when idling, basically) the climate control would turn off, etc. Then the car died and now it won't restart. I just get a click when I turn the key. My dad is still conviced it's probably just the starter, but a mechanic told me this is what would happen (probably) if I didn't replace my dying ECM. Any thoughts?