Re: F-250 diesel batteries die
I had the same problem with my 6.0 Excursion. The voltage regulators fail due to heat. The alternator will then default between keeping the alternator connected to the batteries at shutdown, thus draining the batteries, or making no connection at all. (Don't forget that the voltage regulator does more than just regulate voltage). Make sure the alternator's airflow is not restricted by the hood insulation when you replace the alternator or regulator.