1992 GMC Sierra battery is being drained from its power

Electrical problem
1992 GMC Sierra V8 Four Wheel Drive Automatic

i have no clue what to do. i am not a mechanic but i do like working on my own vehicles my-self. I replaced the tilt steering to a straight steer. then i replaced
the alternator and put in a new battery and still
the battery light comes on. If you send me a diagram
of how to check the charging circuit could you send it so that i can enlarge the picture.
thanks
NewfieTrev.