first check if the engine is connected to the chassis with a copper strip.then turn on the ignition key,pull out the bulbholder of the ignition light,brown/yellow is the alternator site when the engine is not turning this is negative. check whith a simple bulblight,(thake power direct from the + of the battry with one wire and hold the other wire against the brown/yellow the checkbulb must light up, if not there is a neg.problem on the alternator side, if it lights up see if there is power on the green wire, if not check the fuses or any connector for rust and use no corrode battery grease to prevent them rusting especially on the neg. connectors (if the engine is running both sides on your ignition light must be positive)and investing money in a heat resistent sleave for all electrics close to any heat is the best idea.