|
This is copy of an answer I gave a week ago. Hope it helps. Ok, Ross, I assume that you have a 6v positive ground system with no spark and the points and condensor have been replaced. Go back and check the points for the correct gap. Obtain a handheld voltmeter ($8 from Radio Shack). connect the red(+) lead to the tractor frame. Place the black lead to the negative side of the battery. Should get something like 6v. If not, find another place to ground the red lead on the tractor. Move the black lead to the key switch terminals. With the key off, one side of the switch should read 6v, the other connector should read 0v. If they both read 0v, check the wiring between the battery and the keyswitch connectors. Done. Turn the key on, the two connectors should now read exactly the same voltage. If not, remove the tester, short the two keyswitch connectors together and watch you tractor start the first time. (Replace the keyswitch.) Done. If keyswitch voltages are correct, leave the keyswitch ON. If you can get to the resistor behind the dash, carefully probe one side, then the other side of the resistor with your black lead. One side of the resistor should read close to the battery voltage that you got at the keyswitch, the other side of the resistor should read somewhat less (as much as 1/2 the keyswitch voltage). If you are not getting the full keyswitch voltage on one of the two resistor terminals, check the wiring between the keyswitch and the resistor. Done. If one side of the resistor is full keyswitch voltage and the other side is 0v then either a) the wiring between the resistor and the coil is shorted to ground, or b) the resistor itself has opened and needs to be replaced. Note that condition a) might very well cause condition b). Check the wiring between resistor and coil and replace the resistor. Done. If both sides of the resistor show somewhat normal voltages, move to the coil. One side of the coil connects to the resistor you just came from and the other side of the coil connects to the points. Make sure that the battery side of the coil has the same voltage that you read at the resistor terminal. If it is not the same, then check the wiring between the resistor and the coil for opens. Done. If the bat side of the coil has the correct voltage (same as at the resistor), then place the black lead on the other side (the points side) of the coil. Rotate the dist (or bump the starter) until the points are closed (as in the contacts touching each other). The voltage at the points side of the coil should read 0v. Any other voltage than 0v then either a) the points are not closed (regap them, try again) or b) the wire between the points and coil is open (replace the wire). Done If 0v is found with the points closed, then rotate the dist (or bump the starter) until the points are open. With the points open the points side of the coil should read very close to the same voltage as the battery side of the coil. If the points side voltage is still 0v, the either a) the points are not open (regap the points, try again), or b) there is a short in the wiring between the points and the coil (locate and replace wire). Done. Hope this helps. Use the sidebar to the left to search for wiring diagrams.
| 
