New alternator not pushing 14v
 

i bought a 99 f250 5.4l it was fine for a few weeks then the batt light came on, the battery was old so i changed it and the light was still on so replaced alternator. Turns out the old one was fine, checked fuse link it was corroded i cut and put a new connection. The light was still on so then did a draw test, there was a draw of .129mA found a draw on the instrument cluster and a small one on the pcm. My question is can a bad instrument cluster cause the alternator to not charge properly?
the truck will start, but when i put the lights and heat on then raise the plow it will go down to 10v then back up but slowly drain.