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Juan Crespo
Juan Crespo, ASE Certified Technician
Category: Chevy
Satisfied Customers: 1495
Experience:  A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
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1994 s10 blazer was driving died no sprak replaced coil

Customer Question

1994 s10 blazer was driving died no sprak replaced coil pickup coil ignition module any other hits
JA: Thanks. Can you give me any more details about your issue?
Customer: I have power to the coil and the ignition module still no spark
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Submitted: 7 months ago.
Category: Chevy
Expert:  Juan Crespo replied 7 months ago.

Here are the rest of the diagnostic steps GM suggests if power is good to coil and module:

7. Connect voltmeter between ground and tachometer terminal at coil with ignition on. Tachometer terminal may be taped back against harness. If voltage is greater than 10 volts, go to step 9).
8. If voltage is 1-10 volts, replace ignition module and check for spark at coil tower using Spark Tester (ST-125). If voltage is less than one volt, repair open in tachometer lead or tachometer connector. After repairs, recheck voltage at tachometer terminal.
9. Connect test light between ground and tachometer terminal. Crank engine. If test light remains on (steady), go to next step. If test light flashes, replace ignition coil with a known-good unit and recheck for spark. If spark does not occur, reinstall original ignition coil and replace ignition module.

10. Remove distributor cap (if equipped). Unplug ignition module pick-up coil connector. Connect voltmeter between ground and tachometer terminal. Turn ignition on. Using jumper wires, connect positive end of a known-good 1.5-volt battery to terminal "P" of module. Observe voltmeter at tachometer terminal as negative end of test battery is momentarily grounded to distributor housing.

11. If voltage at tachometer terminal does not drop, check ignition module ground. Check for open in wires from ignition coil to module. If all is okay, replace ignition module.
12. If voltage at tachometer terminal drops, check for spark at spark tester as jumper is removed from terminal "P". If spark does not occur, go to next step. If spark occurs, check pick-up coil connections. Check for(###) ###-####ohms resistance at pick-up coil leads. Ensure leads are not shorted to ground. Repair as necessary.
13. Test ignition module with module tester. If module tests okay, check ignition coil wire. If module tester is not available, replace ignition coil, and touch terminal "P" again. If spark occurs, system is okay. If spark does not occur, reinstall original ignition coil, and check coil wire from distributor cap. If no problem is found, replace ignition module.

Please let me know what you find.

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