Sealed Module Connector Distributor w/External Ignition Coil

1. Disconnect a spark plug wire at plug end and connect Spark Tester (ST-125). Check for spark while cranking engine. If no spark occurs, check for spark at other wires. Intermittent sparks are considered no spark. If no spark occurs, proceed to step 2). If spark occurs, ignition system is not at fault. Check fuel system, spark plugs and engine mechanical condition for cause of a no-start condition.
2. Unplug 4-wire EST connector. Check for spark at tester. If spark occurs, replace pick-up coil. If no spark occurs, check for spark with spark tester connected at coil tower while cranking engine. See Fig 1.
   NOTE: Leave Spark Tester (ST-125) connected in this manner during remainder of tests.
3. If spark is present while cranking, inspect cap for cracks or other defects. If okay, replace rotor. If no spark occurs while cranking, disconnect distributor 2-wire "C/+" (coil) connector. Turn ignition on and check voltage at "+" and "C" terminals of harness connector.
4. If there is less than 10 volts at terminal "C", check for open or short to ground in circuit from terminal "C" to ignition coil. If circuit is okay, fault is ignition coil or coil connection. If both terminals read less than 10 volts, proceed to step 5). If both terminals read 10 volts or more, proceed to step 6).
5. Repair wire from module "+" terminal to "B" terminal of Black ignition coil connector or primary circuit to ignition switch.
6. Reconnect distributor 2-wire connector. Check voltage from "TACH" lead to ground with ignition on. "TACH" lead may be taped back to harness.
7. If voltage is less than one volt in step 6), repair open tachometer lead or connector and repeat step 6). If voltage reading is 1-10 volts in step 6), replace module and check for spark as described in step 11). If spark is present, system is good. If no spark occurs, replace ignition coil.
8. If voltage is more than 10 volts in step 6), connect test light from "TACH" lead to ground. Crank engine and observe light. If light blinks, replace ignition coil and recheck for spark with spark tester. If no spark, reinstall original coil and replace ignition module.
9. If light remains steady in step 8), unplug distributor 4-wire connector. Remove distributor cap and pick-up coil connector at module. Turn ignition on.
10. Connect voltmeter between "TACH" terminal and ground. Insulate test light probe to within 1/4" of tip. Note voltage as test light is momentarily connected between module terminal "P" and a 1.5-8 volt source. To ensure against module damage, DO NOT  allow test light to be connected for more than a moment.
11. If there is no voltage drop, ensure module is properly grounded. If good ground is noted, replace module. If voltage drops, check for spark at coil tower with spark tester when test light is removed from module terminal "P".
12. If spark is present in step 11), ensure rotating pole piece is magnetized, replace if necessary. If pole piece is magnetized, check pick-up coil resistance or connections, (resistance should be 500-1500 ohms). If no spark occurs in step 11), check module with Module Tester (J-24642). Replace module if defective. Check coil wire. If wire is okay, replace coil.
13. If module tester was not available, replace ignition coil with a known good unit and repeat step 10). If spark is present, system is okay. If no spark is present, original ignition coil was okay. Reinstall original coil and check coil wire. If coil wire is okay, replace ignition module.

Fig 1: External Coil Spark Tester (ST-125) Hook-Up