SR20det alternator issue

[Covo]

Hey everyone I'm seeking for anyone who can please give me any input on this issue ive had for a year now. Its greatly appreciated. So I installed my SR and bought a plug and play wire harness from wiringspecialties.com to make things a little easier on myself so no wire splicing or anything. The problem im having is the Alternator wont charge the battery. The car will run off the battery until the battery dies and i recharge it. I take a voltmeter to the battery and it is only at 11.7 obviously the alt isnt charging the battery. I changed out the alternator still same problem. I check alternator fuse and the fuse is good. Circuit is good. I checked the power stud on the back of the alternator its only reading 11.7 on the voltmeter. I just changed the alternator with a brand new one still same issue. I checked the wires coming out of the harness from the plug that goes into the alternator with my circuit tester and it lights up shows it is live. Im all out of ideas here. Idk if this is related but only my rpm and temp gauge works on my cluster. I tried putting a new cluster in and now only the temp gauge works on the new cluster. If anyone has any idea i appreciate any help possible and can answer any questions anyone has. Very frustrating been like this for a year now. Haven't had the funds to bring to a shop

[oni jake]

You have a wiring specialties harness. Call them for support.

[Covo]

How are they supposed to help me? I already installed the harness and followed the directions. I dont have the slightest clue to what that problem can be

[zurud]

Check the all the ground