Tractor Repair: farmall 656 ignition points, farmall 656, alternator

Question
my friend has a farmall 656 gas, hydro, with an alternator. he had a small fire in the wiring. since he's repaired the wiring, the ignition points burn out in a very short time. 4-5 hours. can you advise us on what is causing this, and also what should the voltage reading be going to the points. thank you in advance. Stan

Answer
  If the polarity of the ignition coil is backwards, the points won't last very long.  The + terminal of the coil should be powered by the ignition switch, and the - terminal should be connected to the points.  Also, there may have been an ignition resistor in the circuit that maybe is not hooked up now or is bypassed, depending on how he wired it.  The resistor lowers the amount of current to the points so they don't burn as fast.  Not sure what the voltage reading would be to the points.  Check the charging voltage coming from the alternator. It shouldn't charge more than about 13.6 volts with a fully charged battery.  14 volts maximum.  If it is putting out too much voltage, it could burn the points and also cook the battery.