Bmail, Have an alternator Number? I can look up specifics if you like.
As for the wires, the larger one goes on the terminal marked "Bat" and is most likely the alternator output to battery.
As for the other, look for a terminal marked "Ign" (Ignition).
Good luck.
- "In addition, I'm pretty sure that there's an even higher voltage battery specified for trucks."
Unless your talking European , most American trucks are 12 or 24 Volts. The batterys are just in series, or series/parallel to acheve the quantity of current needed to turn over the...
Rob, First off, I don't beleve an inverter will help. They usualy are used to turn 12v (or 24v) DC into 120v AC (In the USA)
My best suggestion would be to add a second 12v battery to the system. If your not familiar with electricity I suggest getting some help from someone that does so you...