No Start No Spark

[Big Doug]

I had the same problem in my 96 2 door Tahoe. This was the fix. https://www.rockauto.com/en/catalog...l-switch+&+relay,ignition+starter+switch,4700

 

[THase89]

I had the same problem in my 96 2 door Tahoe. This was the fix. https://www.rockauto.com/en/catalog...l-switch+&+relay,ignition+starter+switch,4700

What I am struggling to understand with the ignition switch is how does it tie into the coil not firing? Looking at the wiring diagram, the signal is generated from the ICM which I am getting. Both the ICM and Coil are getting 12v power and the ICM is also getting signal from the VCM. Where does the ignition switch come into play?

 

[618 Syndicate]

What I am struggling to understand with the ignition switch is how does it tie into the coil not firing? Looking at the wiring diagram, the signal is generated from the ICM which I am getting. Both the ICM and Coil are getting 12v power and the ICM is also getting signal from the VCM. Where does the ignition switch come into play?

Guessing, but does the ignition switch not cut power to the ICM and coil when it's turned off? Yes, they're getting power when you check them, but as it drives down the road it's turning off? Just thinking out loud.

 

[THase89]

Guessing, but does the ignition switch not cut power to the ICM and coil when it's turned off? Yes, they're getting power when you check them, but as it drives down the road it's turning off? Just thinking out loud.

I would think I’d lose power to everything though right?

A dumb question for the general public… with the key off, should the 12v power wire to coil show continuity to ground?

I’m not an electrician by any means so… happy Tuesday

 

[618 Syndicate]

I would think I’d lose power to everything though right?

A dumb question for the general public… with the key off, should the 12v power wire to coil show continuity to ground?

I’m not an electrician by any means so… happy Tuesday

You would think...but I've seen electronics do weird stuff.
Like I said, just thinking out loud.

Also, check your PM's

 

[THase89]

You must be registered for see images attach

Replaced crank sensor and coil with AC Delco. Relocated coil and ICM and rewired everything from VCM to the ICM and Coil. Ran back through diagnostics and found that the new ICM that tested good prior to this work was now not sending signal to the coil. Replaced and truck is running. Not positive if something electrical caused the new ICM to fail prior to the rewire

Picture is before I cleaned up the wire routing before I get beat up on

 

[Nathan 94]

I don't know how the battery terminals can be a problem if the engine still cranks normally.

Does the coil have power