i really need some help with this car. my 89fwb w/307 is not charging. i tested the volts at the battery with the car running and nothing. just running off the battery. so i took the alternator to the part store and had them test it twice, but it tested fine. i saw for myself. is there anything else that could be causing this or was the alternator test false and it really is bad? i even threw a brand new battery in it to make sure but still nothing.

The large wire that bolts to the back of the alternator must have 12 volts at all times in order to electrify, turn on the alternator. If that fat wire has no voltage from the battery, the alternator will not work! Also put the year and type of Cad you own in your profile signature please.