battery only charging 12 volts or less

[2000proair]

Last year i put a new alternator on my gt40 it charged fine this year it tore the belt to pieces the second day out, put new belt on and worked fine. now it only charges like 12 volts or less i put my friends alternator on and it did the same thing do i need to get the higher output kit on it or is there another problem ???


i got two batteries with a few amps and alot of speakers so maybe thats the problem

[mrbobolina]

are you only getting 12 with everything turned off? are you running a perko between the batteries?

[GC]

Are you going by what the gauge reads or have you checked it with a volt meter?

[h2ohangtime]

Check the tension on the alternator belt as well...I've had problems with it slipping and that has caused the volts to be lower ~11 or 12.