1997 chevy s10 blazer

hey there. I recently bought a 97 s10 blazer, it was cheap but needed a new motor and a little tlc. Ive got the new motor in and running great but im not getting a charge from the alternator. All wires are plugged in to the right connectors and all the grounds are grounded. I took the alternator to two different part stores to be tested and 5 out of 5 times it was good. I’m wondering if maybe the cluster could have something to do with it not charging? I figure the battery light and the amp meter are tied in to the same circuit. my cluster has been out before i bought it  and was just placed in there without the lens, registering 125k i assume the miles were rolled back. I haven’t taken it completely out yet because not having a tilt column i will have to take the plastic pieces under the dash off to drop the column to get it out and i  wasn’t sure if it would help my problem anyways. I have pulled it out as far as it would go before being stopped by the column  and tried to get it seated correctly quite a few times. Each time i do its something different one gauge or light that didn’t work the previous time will work then do it again it may not work, but i HAVE had all the gauges and lights working just not at the same time. Is there a specific technique to getting it back in and seated right? Also is there anything in particular i should look for if i pull it completely out? sorry for such a long message just thought i would give the best description of situation possible. Thank you very much for your timr and your concern any and all feed back would be very much appreciated…