so i have been having some electrical issues in my 03 civic lx coupe i just recently swapped engines a month ago and been trying to fix the tweaks since. so atm the alternator is getting power to 3/4 pins in the light green connector on the alternator 1 wire is giving off 13.4v because i charged my battery right up and its giving that reading and 2 others are low voltage 5.3v and 4.7v (videos below to see) and then the ground ive chased the wires and they seem to be good checked the alt fuse under the dash and replaced it with a new 10amp and some people say the fuse 15 problem well thats good too i also went out bought new battery ground cable and cleanned everything right up so they are nice solid grounds please i need some help with this

If it's an aftermarket alternator return it and go get an OEM one from the junkyard

i cant return it

I suggest you do a load test on you battery and alternator. You can search YouTube on how to do it. You'll need a multimeter though.

Well sell it to someone else then