To answer camricer.
The volt meter will let you know your battery condition and charging system.
An ideal,new batterys voltage is 12.6 Volts.
An running, idle cars alternator output will be 12.8 to maybe 13.8 volts
At speeds above 1500rpm, and alternators output should be from 13.8 to 14.4 volts.
At this range is where you get the most power out of the alternator, and does the bulk of recharging to the battery so your car can start next time.
Most car electronics, oem or aftermarkets minimum voltage requirement is 10.8 Volts.
The ignition system on most cars will crap out at about 9 volts.
Also, is that a 1MZ I spot?
Also might want to slap a tiewrap or two on some of those wires running to your alternator. You wouldn't want them to fall or slip and get into a fight with your serpintine belt.
