1998 Mitsubishi Eclipse RS 4 cylinder, we wee.

1998 mitsubishi eclipse rs 4 cylinder, we wee going down the oad, ca ran hot, we replaced the thermostat. Now battery lights on, we buy a used alternator, didnt fix it, batterys overcharging. WE buy anew alternator, didnt fix it, battery lights still on & its still putting out too many volts. Volatge regulator is internal in alternators. We take it & have it diagnosed, they say we need a new ecm, we buy a new ecm. Doesn fix It STILL has battery light on, tll overchaging. What could it be, PLEASE HELP US. I dont have a credit card to make a donation, if I did I would gladly make one. Is not a turbo.