94 dodge ram 250 5.9 no spark

initialy pulled crank shaft sensor (real greasy) wiped cleaned and reinstalled, started right up,, not driven in a week after, battery was dead, jump start but no spark, relpaced crankshaft sensor, no spark// battery does not hold charge ok but with jumper is it produceing enough to trigger ecm/pem/icm whatever// also replaced distrubutor pickup, no spark and no power to coil// is there a start wire diagram available or has anyone experienced this///only left is brain, asd relay/ ing switch/  how to test these help please if you can

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wiener20

First off is to determine battery condition - recharge and if it fails to hold power/voltage, replace.


If jumping or otherwise, ensure the ECU isn't in limbo - give it at least 10 seconds disconnected (pull its fuses or disconnect the main battery).   

If the coil has no +12V, then no spark. Check its fuses and connectors.

Spark can be checked with +12V to the coil and making/breaking its -ve side to GND. This can be done still in situ - ie, a parallel grounding won't (or shouldn't!) hurt ignitors or points.


If it isn't sparking when cranking, then start circuit analysis - ECU power etc.

I suggest the standard disconnect & reconnect of connectors, and a rotation of (same sized) fuses and fuselinks.


PS - maybe the sensor's wires have broken? But try a disconnect/reconnect.

Not sure how the OEM security works on the vehicle but it is possible that the coils are not powered if the security system isn't satisfied by the right key. As OldSpark said check for power at the coils and make sure they are getting power. If not, trace the circuit back and find out where the power is being dropped.

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Kevin Pierson

Ha, just saw this is a 94 - doubt the truck had OEM security. How many coils does the truck have?

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Kevin Pierson

thanks for feedback guys, i traced wires and connections, found just to front of altenator a big black harness that had a green corrosion 3 inches from connector,, peeled back harness tape and a red wire// constant hot had a perfect hole in wire // no wire but insulation intake //wierd// soldered that wire// but still no spark/// but gave me check engine light which i did not have//  so i followed oldspark coment on disconnect and reconnect ( asd relay, ecm, etc) started after unplugging  ecm and replugging and has been fine so far///wow thanks again guys

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wiener20

LOL - thanks for your feedback.
Nice to know that the "95% of fixes" tip still works. (What a pity more vehicle mechanics don't try it!)