Well, I've asked this question myself. Yes, you can start the truck with a 12v battery. You can take the battery, hook it up as normal, and if it's anything like my truck(which by the way, what year do you have?) disconnect the smaller wire on the starter. Then disconnect the positive on the coil and place a wire from the starter to the + on the coil. Don't forget to tape up the ends off the wires you disconnect and either label them or remember where they go. After this, to be safe(I'm not clear on this myself if you have to do this part) disconnect the wires on either the generator or the voltage regulator. The regulator, if you don't know, is a black box on the firewall about the size of a spam can. You can verify this by following the wires to the voltage regulator from the generator. That's what I was told when I asked the same question. You can also, if you want to, go through something I found a little harder and disconnect the temp/oil/gas/amp gauges and then the generator and leave the rest alone. But after one of those two hook up the battery and start it up(first method doesn't require a key but second does)
