Vehicle has a no spark no fuel condition, electrical diagnostics and diagrams needed?

Tiny
94KOTA21
  • MEMBER
  • 1994 DODGE DAKOTA
  • 3.9L
  • V6
  • 4WD
  • MANUAL
  • 240,000 MILES
Vehicle has no spark no fuel condition. I've replaced the famous junction located under the fuse box in the engine bay I have power into and out of the ASD (Automatic fuel shutdown) relay something strange I noticed is that the shift light is now constantly illuminated when the vehicle has power regardless of when the key is turned one question I have is where does the PCM get the signal to activate the shift light I'd assume cam and crank signal so following up on that question if its constantly illuminated could that mean there's a short somewhere either in the sensor wiring or one of the sensors themselves causing it to have constant signal from there to the PCM leading it to not pulse for the coil when I turn the key the fuel pump also does not run at all and the CEL never comes on and I mean never not even when the key is cycled I replaced the PCM thinking it just wasn't communicating but with a used confirmed working PCM the problem continues the cam and crank sensors as well as the coil distributor cap and rotor have all been replaced but something to add is the problem occurred from bad alternator wiring shorting out that problem has since been fixed but maybe that took out the new cam or crank sensors because those were replaced new before this issue for a separate rough running issue I know this problem is wiring related because it's a brand new short block with mostly new parts on it any diagrams available for the engine and cluster wiring would help immensely or maybe some insight to the problem itself.
Tuesday, April 22nd, 2025 AT 8:22 PM

4 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 52,325 POSTS
Power to the PCM come from fuse C and D in the fuse panel under the hood. I would check those for power first, then make sure the PCM grounds are in good shape which are on the rear of the intake manifold.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

The shift light comes from the PCM programming but it can be because the PCM does not have the correct power input or grounds. With the key on do you have power to the DKGRN/ORG wire at the ignition coil? Here is the engine the PCM wiring diagrams so you can see how the system works. Please go over this video as well.

https://www.youtube.com/watch?v=lXLJbuAZ4CE&t

Check out the images (below). Please let us know what happens.
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Wednesday, April 23rd, 2025 AT 9:47 AM
Tiny
94KOTA21
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  • 3 POSTS
Yes, I have power at the dkgrn and org wire at the coil, but when I crank there's no pulse on the grey wire. If I used the new PCM I got, would it need reprogrammed surely, it's too old for that I'm thinking it's definitely a short somewhere though the wiring diagram will definitely help.
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Saturday, April 26th, 2025 AT 4:57 PM
Tiny
94KOTA21
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OMG, thank you. It was the PCM Ground. I had it in the wrong location fired right to life when I put it on the intake manifold thank you so much, I'll be leaving a hefty donation as I've been dealing with this for months and nobody could figure it out.
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Saturday, April 26th, 2025 AT 7:37 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 52,325 POSTS
YAY! It is great when we can fix them! Happy motoring :)
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Sunday, April 27th, 2025 AT 12:17 PM

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