similar problem
Did you upgrade the charging wire also? This is a must for this unit.
I had the same basic problem a few years back. When I bought my car the alternator casing was cracked, so I went with a 200 amp unit. But still could not get it to charge. Turned out that I needed a field fix unit from Casper's. Once that was installed charging around 13.5-14 while moving.
Turns out I had an issue with my dash which was causing the problem. Later I found out it is very common. Do a search on alts, I'm sure it will turn up.
Evaddave
just saw your second post. You better check that aternator out first. Take it out and run it to local Auto-Parts store. Most will check it for free. If you can determine that is good then proceede. Also if the previous unit was charging fine, then this unit is the most like charge.