41 "Alternator field circut open or shorted"

bought the truck a few weeks ago with this code stored so i dont know if anything was changed before it came up or how long its been on. tried cleaning all the connections i could find, deleted the code with an obd 1 scanner and it comes back instantly it actually doesnt seem to ever even clear. i tried leaving the battery disconnected for a half hour. connected it and turned the key on and off for the cel to display codes and got "4" "1" again without ever even starting the engine. so this is something the computer knows is wrong as soon as the battery is connected.

battery is fully charged (12.7V) and the alternater is charging at over 14V. the volt gauge on the instrument panel seems to work fine and i havent actually had any problems or symtoms of a bad battery or alternator other then the check engine light trouble code itself.

totally stumped thanks for any help guys.

 

At idle what is the voltage? If it is 14v at idle that is too high typically.

The typical reason for code 41 is a bad alternator. Most autoparts can test it free off of the vehicle.

The next reason is bad wiring or a bad PCM.

 

yeah its just over 14V at around 700 rpm
ill probably start with having it tested then

 

had the alternator tested and its good. maybe the pcm. the ecm and pcm are one module in that truck correct? just weird because everything works fine the light is just on