Ok, heres my problem on my 82 F100. My last battery which was old would not show more than 12.25 volts. I replaced the alternator, voltage regulator, and put a brand new DieHard Gold battery in the truck. The brand new battery had 12.57 volts when I bought it. After starting the truck the battery was showing 12.37 volts. The truck starts fine and after you shut it off the battery goes back up to 12.57 volts. At my voltage regulator with the engine running I am getting 12.37 volts at output A. At output S im getting 11.85 volts. At output F im getting Zero volts. Output I has no function. With the key off A gets 12.37 volts. Outputs S and F get zero. Now my problem in guessing is that since im zero volts at F mean that I am not getting any current flow through my field. Any help? Thanks Fred

 

With the voltage reg. disconnected, engine running, jumper a and f terminals to "full field" the alt. My book shows the I terminal is the ignition switch input to turn the regulator on. "I" should have power through the gauge or idiot light to trigger the reg.

 

Thanks for the help, I found out a the field portion of the voltage regulator was bad on the new one I had. I hate when you get new parts and they are deffective. Fred