Heres my story...

Today After class got out, went out to drive home. The battery was dead. I figured I had left a light on. So I got a booster pack and jumped it. Started and ran fine, although the volt meter read lower than it usually does. after a few hours after getting home I went out to start it again and the battery was just about dead again. So I though maybe one of the plates inside the battery took a s***. Went to change the battery, but while doing so when I would connect and disconnect the terminal I could hear a faint buzzing type noise. So now im thinking there must be excessive parastic drain (ignition off draw current) causing the battery to go dead. I was right. There was about 100-150 milli amps being drained with the ignition off. More than tripple what it should be. I began pulling fuses to see which circuit was draining however it never stop draining no matter what I pulled. Finally I found that when I disconnected the connector to the voltage regualtor on the alternator the buzzing would go away and drain would drop to about 35 milli amps. Oviously something is wrong with this circuit, however I do not know enough about how ford regulators work, so that is why I need your guys help.

What I really need to know is, Can a bad regulator be somehow shorted to ground and causing it to feed current to the alternator rotor with the ignition off? Do you guys think maybe the ignition switch could cause this? Please, if anybody could give me some info on exactly how this works, or where to go from here, that would be great.

 

i do believe the newer ones are built in to the alt. like since middle 80s-helped a mechanic down the street put one in a chebby alt.was cheap to buy but what a pain to put in-he said he would never do it again! just knuckle up and buy the whole thing

 

take the alt off and have it tested.

if you do need one do not buy the cheapest one.

 

Tweaked: If your truck is in the years of this forum, the regulator is fairly easy to replace, but you will need to remove the alternator first. Not knowing exactly which alternator you have, I can only give general instructions: There should be some holes through which you can put some small nails or wires to hold the brushes away from the rotor while you remove/replace the regulator.

 

This probably doesn't apply here, but I remember back when I was a kid, my dad and I plus several mechanics in town went in circles for over a month with our 1955 Dodge (generator) draining battery because of voltage regulator staying kicked in with car off.

Finally someone noticed that the engine to body frame ground strap was broken.

After 3 regulators and with that repaired, all was good again.