Alternator not charging battery

[broncobeast75]

Yesterday I Found the battery on my bronco dead. So I hooked it up to the charger and it fired right up. I drove it around for a while and then parked it. came out to drive it again and it was dead.

Last month I had a strage issue where I turned the ignition off but the motor was still running. I had to start the motor again to turn it off.

I replaced the alternator on my 75 about 6 months ago and the battery was replaced about 2 months ago. I Had the battery tested and it was good. I had the alternator tested and it was not putting out anything.

Should I go get a new alternator to see if that fixes anything or is their something else I should look at?

 

[Cready1]

I just had the same issue with my 73; the alternator was not charging so we decided to dig a little deeper before replacing the alternator. Found out it was not the alternator but I was not getting power from the ignition switch via the red/green to the voltage regulator due to me running a straight wire from the switch to the coil when I upgraded and did not realize the wire also went to the volt regulator.

 

[Viperwolf1]

First take some voltage readings from the battery before and after starting. That will tell you if the alternator is working. A broken ignition switch can cause a drain that will kill a battery in one day.

 

[tatersalad]

make sure that the contacts at the regulator are clean, I had my alternator not charge the bat when i upgraded the intire charging system years ago and that was the culprit..

 

[broncobeast75]

I took the alternator off today and had it tested. They said it was good. I think I will try the ignition if no one has any other opinions

 

[ronnie90]

i had same problem after my engine swap turned out i hadn't grounded the alternator... easy fix but i felt dumb,

 

[ronnie90]

have you made sure all your wiring is hooked up right and not compromised? could have a wire shorted or something.

 

[bronconut73]

Is there an easy way to tell if my charging issue is my alternator or voltage regulator?

 

[Viperwolf1]

Is there an easy way to tell if my charging issue is my alternator or voltage regulator?

Yes. Measure voltage on the orange field wire between the alternator and regulator. Low or no voltage indicates a regulator problem.

 

[bronconut73]

Yes. Measure voltage on the orange field wire between the alternator and regulator. Low or no voltage indicates a regulator problem.

I knew you would respond Viper'. Thanks Bud.

 

[ronnie90]

I just replaced my voltage regulator anyways. I thought since I was messing around under there might as well get rid of a 30 year old piece of electronics and rule that out...

 

[ronnie90]

If you really don't wanna mess with it go see if you can score an internally regulated alt from a Taurus at your local scrap yard. There's a lot of threads on which one to grab.