[MoBell412]

Im very green when it comes to these carts and their workings, and im having some starting issues with my 1983 marathon. Im getting 12v at the battery before cranking, and the motor will crank and crank ( quickly at first, then more delayed after the first few turns) but wont fire up. If I hook up jumper cables it'll crank right up and run with force but when I take the cables off it slowly dies. My first thought is starter/generator. I checked all the cables and connections and they're old but still very much intact and tightened. Most of the wiring other than these thick red cables looks like they were rigged up by the previous owner. Any one have a wiring diagram for this? Im finding a lot of wires that were cut, most of them being ground wires. Any input is appreciated. I have an automotive multi meter but honestly don't know where to begin other than checking the battery for 12 v . Im not sure how to locate anything else because like I said, Im extremely new to all this. Thanks in advance,
-Matt