I have a '70 Maverick, straight 6, 3.3L. I was having batteries die on me about 6 months ago within weeks of each other. I put new belts on and that seemed to help... until now. I put a new battery in today and when I when I turned the car off after driving a couple miles, the ALT light came on and stayed on EVEN when I pulled the key out!! I disconnected the wires, put them back on and it sounded like a click in the voltage regulator was going on, but the ALT light was still on. It is now disconnected and awaiting my tlc, but I have no idea... Suggestions? (I do think my left reverse and stop lights are burnt out, but - bleh!) -David
I believe it's going to be a diode bad but in the alternator. As suggested, take it to one of the parts stores. They usually check them for free. If it is the alternator I would recommend changing the regulator with it.
Diodes don't click.. The relay in the regulator does when power is applied to it. the regulator is either shorted or there is power going to it with the key off. A bad diode will allow the battery to drain but it won't affect the regulator and it won't make a click. If you pull the alternator battery wire off the solenoid and put a 12 volt test light connected to the wire and the solenoid you can tell if there is a shorted diode. If the light comes on then it is a shorted diode. If the light stays off then the diodes are fine. Test the "I" wire in the regulator plug for power with the key off. If there is battery voltage there then you need to find out where it is coming from. It is only supposed to be "hot" with the switch ON.
