"The 1972 100hp model incorpor
"The 1972 100hp model incorporated the Battery Capacitance Discharge ignition system, which means that the powerpack is actually what is a pulse pack and requires battery voltage to energize it.
With the engine NOT RUNNING, check the purple wire leading to the pulsepack. When the key is OFF, there should be No Voltage being applied to that wire. With the key in the ON position, 12 volts should be applied to that wire. If this holds true, turn the key back to the OFF position and the voltage to that wire should drop to zero. If this test holds true throughout, the ignition switch is okay.
You cannot mix the different color electrical plugs. The wiring and the control box circuitry itself are different. A yellow plug must be connected with a yellow plug, black with black, red with red.
If the above ignition switch test proves the switch to be okay, what is happening is that the charging system is providing voltage to the pulsepack as long as the engine is running.
There should be a small diode attached to the ignition switch that connects to the voltage input terminal of the shift switch to prevent thiss from taking place. The diode must be attached so that voltage flows from the ignition switch to the shift switch. Check your old control box and transfer that diode over if it exists. Pay attention to what terminal it is attached to.
When time permits, visit my eBay store at:
http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store"