97 5.9 with no spark looking for ideas

[mjnoe70]

1997 Ram 5.9 Magnum has no spark at the coil from what I can tell. I'm not 100% sure how to test that though...

What I've done, in order:
Checked Fuses
Replaced Plugs
Replaced Rotor and Cap
Replaced Ignition Coil
Replaced Crack Shaft Sensor
Replaced Cam Pick Up under Rotor


Tried testing individual plugs using both ground contact testing and with a testing bulb with nothing. So tried to direct connect the output from the coil pack as well but nothing seems to be happening. I did the first 3 items before I realized the spark was not getting to the plugs.

I have debated changing out the ignition switch but the motor turns over when I turn it to the start position. Is this my next logical step or would I be barking up the wrong tree? I don't see anything "electrical" as part of the ignition switch. Is there any other idea of something to check/test?

 

[GTyankee]

Does it have a resistor ?

 

[mjnoe70]

No, it appears to be a single unit...

 

[Skatulaki]

Start at the cable plug on your coil, unplug it make sure you dont have any burned or broken connector pins or slots, make sure clean and fully seated, if no fire, follow the cable back to its next device, which may or may not be the fuse box. Make sure you do not have any burned broken or shorted wires, harnesses can sometimes over the years get relocated and short out. Not having a readily available wiring diagram, but I'm sure you can google one. If engine turning over, ignition switch is definately barking up the wrong tree.
Basic electrical trouble shooting is , you should have a certain reading at a certain pin throughout the circuit. Trace back through each connection until you find where you are getting your reading again. somewhere in between is where the problem is. A bulb tester is ok to use to see if you have voltage or not, however it is useless for testing continuity. You need a multimeter for that. I'm thinking that its the ECM ( the big money box ) or you have shorted harness between that and coil.
I can look at mine tomm after work. Multimeters are cheap at harbor freight, and easy enough to use if you know what the symbols mean. Hopefully there is a common issue, where somebody can say, Oh its probably this. Good Luck

 

[Bear_Gibson]

Make sure one of the low voltage terminals has 12 volts positive with the key on, the second wire comes from the computer. I believe there is a relay called A.S.D. that powers the coil. Do you have an engine light on? You might be able to test the low power side with a bulb, I'd use a LED bulb as it will light faster. Get a helper to turn it over, the bulb should blink when turning over if you connect to both coil low voltage terminals. I don't know if it will power it long enough to see it.

1996 manual, same as 1997 trucks.
You can download this manual.

1996 Dodge Ram Service Manual.pdf

drive.google.com

 

[Bear_Gibson]

ASD relay Location in PDC fuse box under the hood.

 

[Skatulaki]

I looked at mine the other day, and the wiring from the coil goes up by the alternator, runs along between the passenger side valve cover and intake, then loops up into a plastic harness holder that runs across the top of the firewall. From there they can go toward the ECM, on the passenger side, or fuse box, right side. As per the previous posters info, check the circuit at the fuse box and ECM according to the wiring diagram. If you have fuses that blow, or other suspicions of grounding out. The most likely place for shorting or burnt wires, IMO will be the cable running between the Firewall and coil.

 

[mjnoe70]

Thanks @Skatulaki but I am not having any fuse issues I can find. I have checked all internal and external fuses. Based on prior responses, I did order a replacement PCM. With that I seem to have spark now but it still doesn't start. It seems to get close to running but then almost has an odd noise/possibly backfire and just returns to continuously turning over with nothing until it does that again. I did have someone over help me so we could test for spark and I do have it after replacing the PCM. I did move the relays around just to see if maybe that would help. If so I'd have purchased a new one.

It almost seems like the timing is off but I've had no indication of timing issues before. I have reviewed and double checked the wire firing order and all seems to be what it is supposed to be.

<--- Block
2 4 6 8 (passenger side)
1 3 5 7 (drivers side)
Order 1 8 4 3 6 5 7 2

 

[Skatulaki]

I just went out and looked at mine, the firing order is on the intake manifold and is indeed 18436572, Google the cap positions and verify that you also have them in the proper rotational order. It is easy enough to get them all one off in rotation, or opposite rotation. one screw on the cap has a square mount , the other oblong , and there is a vent on the cap, use those as guides!
Assuming that you already have these in correct order. ( I'm not there so I choose to believe you ) You may have a secondary problem like fuel flow. Spray a little gas in the intake, not too much, and see if it lights up for 3 or 4 sec's