CDI Electronics Outboard Ignition Troubleshooting Guide

91 Mercury Troubleshooting Mercury Mercury 1970-1975 Four Cylinder Engines (With 333-3213 Switch Box) (With Ignition Driver Distributors) WARNING!! DO NOT CONNECT 12VDC TO THE IGNITION MODULE AS DC VOLTAGE WILL SEVERELY DAMAGE THE SWITCH BOX AND IGNITION DRIVER. NO SPARK ON ANY CYLINDER: 1. Disconnect the Orange (or Blue) stop wire AT THE SWITCH BOX and retest. If the engine’s ignition now has spark, the stop circuit has a fault. Check the key switch, harness and shift switch. 2. Check the cranking RPM. A cranking speed of less than 250-RPM will not allow the system to spark properly. This can be caused by a weak battery, dragging starter, bad battery cables or a mechanical problem inside the engine. 3. Check the Ignition Driver resistance and DVA output: WIRE READ TO FUNCTION RESISTANCE DVA (Connected) Red White wire Cranking Winding 400 ohms 180-400 V Blue White wire High Speed Winding 10 Ohms 25-100 V Green Engine GND Pack output N/A 150 V + White Common for Ignition Driver (DOES NOT CONNECT TO ENGINE GND) 4. Check the Ignition pack resistance: RED METER LEAD BLACK METER LEAD READING Red Terminal Pack Case Ground Diode Pack Case Ground Red Terminal Open Blue Terminal Pack Case Ground Diode Pack Case Ground Blue Terminal Open White Terminal Pack Case Ground Diode Pack Case Ground White Terminal Open Green Engine Ground Open Pack Case Ground Green Terminal Diode NO SPARK ON ONE OR MORE CYLINDERS: If only one or two cylinders are not firing on this system, the problem will be either in the distributor cap or spark plug wires. Two Cylinder Engines 1974-1985 (With 114-6222/ 3 39-6222/339-5287 Switch Box) SERVICE NOTE: These engines require the Orange, Red or Green Ignition coils. The Black or Blue ignition coils use a common ground connection internally for the primary and the secondary side of the coils. This system requires that the primary and the secondary side of the coils be separate as the pack drives the negative side of the coil to ground, causing the coil to generate spark on the secondary side. NO SPARK ON ANY CYLINDER: 1. Disconnect the Orange stop wire AT THE SWITCH BOX and retest. If the engine’s ignition now has spark, the stop circuit has a fault. Check the key switch, harness and shift switch. 2. Disconnect the Yellow wires from the stator to the rectifier and retest. If the engine sparks, replace the rectifier. 3. Check the cranking RPM. A cranking speed of less than 250-RPM will not allow the system to spark properly. This can be caused by a weak battery, dragging starter, bad battery cables or a mechanical problem inside the engine. 4. Inspect and clean all engine and ignition ground connections. 5. Check the stator and trigger resistance and DVA output: WIRE READ TO RESISTANCE DVA (Connected) DVA (Disconnected) Orange Engine GND 1600-1800 (800-900 per coil) 180-400 V 180-400 V (*) Brown White (or Brown) 140-160 0.5 V + 0.5 V + (#) (*) This reading can be used to determine if a stator or pack has a problem. For instance, if you have no spark