2 ) Check the voltage on the red (or purple) wire at the CD unit. If
the voltage is less than 9’/z volts during cranking there is a problem in the battery
circuit. These units require at least 9’/1/2 volts to fire properly. Connect a jumper
wire directly from the battery (+) terminal to the red (or purple) wire. Retest.
ATTENTION: In order to kill the engine if it cranks, the jumper wire must be disconnected
and/or choke the engine. If the engine still fails to crank, recheck voltage as above. If
low, replace battery and retry.
3 ) Disconnect points and/or sensor wire and connect a battery tester.
Hook up the Battery CD Tester according to the operators manual and align rotor with spark
plug wire. Connect a spark gap to all spark plug wires and turn the ignition switch on. If
the CD unit fires to only one spark plug wire, check the points, sensor, anti-reverse
spring and wires for breaks and shorts. If ANY other
spark plug wire fires besides the one the rotor is aligned with, the distributor cap
and rotor should be replaced. The Battery CD tester will fire the system to approximately
3000 RPM. If the Battery CD tester (511-9701 ) is not used, strike points wire against
engine ground. For the sensor, strike the two sensor wires together. The CD unit should
fire every time. If the CD unit fails to fire, it is usually bad.
4) Points type ignition. Disconnect points wire and check voltage on the
points wire. You should read close to battery voltage with the key switch on. No voltage
means a bad pack. If OK, reconnect the points wire. Using the piercing probes (511-9770),
connect the DC volt meter to the points wire. Turn the switch on and slowly rotate the
flywheel. You should see the voltage fluctuate up
and down.
Check the ignition coil. An open, cracked or poorly grounded coil can
burn out a battery CD unit.
6) Check the DVA voltage on the primary input wire to the coil. Reading
should be approximately 200 volts or more.
7) Simplified bench test:
