Originally Posted by AQTahoeZ71
....it drops to like 10.3. from 14.6....
Please, for the love of god, do NOT let it get that low again. Until you get a 270XP
or something, keep a close eye on that voltage. Anything lower than, sort of 12v is bad. Some people drop to mid 11's but I wouldn't.
As said, ONE 270XP should see you right. If you upgrade at a later date, get another.
The thing about alternators is; in stock form they are only mildly 'tuned' (if you like). For instance, I have just bought a run around, it has a 70A alternator that, unless I'm sitting over 2k rpm (not very often - diesel) I am only getting 40A from the bad boy!
Your stock one, I suspect yours is only putting out 90 odd amps at low rpm/idle, that right there is your problem.
Are any of your 0awg runs, negative? As in, alternator casing to rear batteries? If not, I'd change one out - see if your voltage stabilises any...