All Kettering ignition systems work the same way, regardless of voltage or polarity. There are some minor differences in details with polarity and voltage, but general operation is consistent. Here's a quick way to check what's going on using a test light. You can use a 12 volt light on a six volt system, it just won't be very bright. You can also use an analog meter, but a test light is easier to watch. Digital meters don't do well at measuring pulses... First, check to make sure the light is working and has a good ground. Attach the clip to a ground and touch the probe to a known hot source or the hot battery post - light should light. Touch the probe to the following points, crank the engine, and observe the light: Hot (battery) side of coil - light should be "on" steady. No light means you're not getting power to the coil. Light pulsing on or off, or varying in intensity, means you have a high resistance connection somewhere in the power circuit. Point side of coil - light should pulse as the points open and close..."on" when points are open, "off" when points are closed. Steady "on" means either the points aren't closing or the wire between the coil and points is broken. Steady "off" means either the points aren't opening or something (most likely the wire between the coil and points) is shorted to ground. If the points are in fact opening and closing correctly, as indicated by the test light pulsing when the engine is cranked, you should have spark at the output of the coil. You can check this by pulling the coil wire from the center of the distributor and holding the distributor end near the engine block while cranking (not with your fingers unless you like getting zapped). You should have a nice fat blue spark at least 1/4" long. No spark at the output of the coil (and asuming the points are working correctly as determined above) means either a bad coil or a bad condenser. A weak yellow spark is generally a bad condenser. If you have spark at the output of the coil, reconnect it to the center post of the distributor, and repeat the check for spark at the end of one or more spark plug wires. If you have spark at the coil but not at the plugs, you most likely have either a bad/broken rotor, a bad distributor cap, or bad high tension wires. If you have spark at the plugs, check to make sure the distributor was timed correctly when the engine was assembled. As each cylinder comes up on compression, the rotor should point to the corresponding terminal on the distributor cap. If you set static timing so that the points just open (use the test light) at top dead center, the engine should run. Once it's running, you can set timing per the applicable manual. Keith
