Need to find info on the location of the voltage regulator on a 1989 ford f150 truck
Preferably a diagram but any info at all will help, I have the new part cannot locate it under the hood.

Bought a new battery yesterday morning, drove 45 minutes to work... all fine, drove home the same amount of time at night with the lights on, the battery was drained to where it cranked just a little, got a jump start and it was fine, let it sit overnight and it was so dead it would not crank.
My guess is the voltage regulator, cannot locate it in the engine compartment.
My next 2 guesses would be an open circuit (any ideas where ? Could it be in the regulator ?) or the alternator, thought the regulator would be a safe place to start.
ANY HELP WHATSOEVER IS REALLY APPRECIATED

Diagram for location ?

The voltage regulator for this vehicle is built into the alternator it is not and external one that bolts to the body[underhood compartment]