Which wire on the alternator? There's three of 'em. Which battery terminal? There's two of 'em. If you ran a wire from the battery positive to the large alternator output wire, the fuse will blow as soon as the system demands more than 20 amps, which is pretty soon. It takes 10 - 15 amps to run the fuel pump, injectors, ignition coils, and computers. Add brake lights, heater fan, head lights, (pop), and we haven't even talked about recharging the battery yet.
If the wire goes from the battery positive to the orange / dark green wire, you bypassed a 20 amp fuse "T" in the under-hood fuse box.
If the wire goes from the battery negative to the dark green wire, you bypassed the voltage regulator in the Engine Computer. That will lead to overcharging the battery and popping light bulbs and computers. This is how the "full-field" test is performed when testing an alternator. Damage will start to occur when you increase engine speed. If you measure battery voltage, it must be between 13.75 and 14.75 volts. If it is higher than that, and if it goes higher when you raise engine speed, you're going to start damaging stuff.
Thursday, January 27th, 2011 AT 7:14 PM