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Troubleshooting for OMC Amplifiers, Pulse Packs, Power Packs, and CD's

Re-write of OMC Technical Bulletin


TROUBLESHOOTING MOTOROLA/DELTA/WABASH AMPLIFIERS FOR OMC ONLY


A large majority of the problems associated with the Motorola and Delta units are due to low voltage battery input or grounding.

LOW VOLTAGE SYMPTOMS ARE WEAK SPARK OR SELECTIVE FIRING (WEAKLY) OF INDIVIDUAL CYLINDERS.
1) Check all battery and ground straps and connections.
2) Check the voltage at the red wire on the Motorola unit. It must be a minimum of 9.5 volts at cranking speed. If the voltage is less than 9.5 volts, disconnect the red wire and run a jumper wire from the battery positive (+) to the red wire and try cranking the engine.
ATTENTION: DISCONNECT THE RED WIRE TO KILL THE ENGINE
3) Check points. Test unit with distributor lined up with spark plug by touching the points wire to the ground with the ignition switch on. The spark plug should fire.
4) Check the coil. An open, cracked, or poorly grounded coil can cause a Motorola type unit to burn out.
5) Check voltage output at blue wire (coil). Must be approximately 200 volts (CD 77 Meter) at 9.5 volts input on red wire.
6) Simplified bench test:
Image

NOTE: RED WIRE MAY HAVE FADED TO A PURPLE OR PINK COLOR.


TROUBLESHOOTING PRESTOLITE/WABASH PULSE PACKS


The Pretolite Phase I & II packs generally are affected by the same problems as Motorola, and are tested the same way, except the inductive sensor replaces the points. Prestolite packs will not operate properly at less than 9.5 volts. Touching the sensor wires together should produce a spark with the distributor lined up and the ignition on.

The bench test for Prestolite is the same as Motorola except the two sensor wires should be touched momentarily. (NOTE: THIS DOES NOT SIMULATE THE SENSOR INPUT.) For a more accurate test, use a good sensor and pass a screwdriver shaft next to the sensor face.

Check for broken or shorted wires, especially in the sensor area and distributor base.


TROUBLESHOOTING OMC POWER PACKS AND CD'S


1) UNIT WILL NOT FIRE:
Check for broken wires on the unit or stator. Check voltage output from stator, should be approximately 250 volts (CD 77 Meter).

2) CYLINDERS 1 & 3, OR 2 & 4 WILL NOT FIRE:
Check sensor wires and sensor ring. Sensor may need regaping. Use gap gauge P/N 97-2, page 6.

3) ENGINE WILL NOT SHUT OFF:
Check kill wire. If you run a jumper wire from the black/yellow stripe kill circuit to ground, this should kill the engine. If not, the pack is defective.

4) PLUGS WILL NOT FIRE IN ENGINE, BUT WILL FIRE OUT:
Starter is dragging, low RPM or low battery is causing low RPM cranking speed.

5) CD 3/6, CD 4 & PP 6 RUNS ROUGH ON ONE BANK:
Blocking diode failure in the pack on the opposite bank.

6) INTERMITTENT FIRING OF 1 OR 2 CYLINDERS:
Low voltage from the stator or bad wire contact internally in the sensor ring.

NOTE: HIGH VOLTAGE COILS ON THE OLD STYLE STATORS SHOULD NOT BE CRACKED OR LEAKING. THE STATOR SHOULD BE REPLACED IF THE COIL IS LEAKING A TACKY/GUMMY TAR LIKE MATERIAL.

CD UNITS HAVE A PROBLEM WITH BROKEN WIRES. CHECK THESE CAREFULLY, ESPECIALLY AT THE AMPHENOL CONNECTORS.