No crank, no fuel pump, no start

DanTheBetterMan · September 11, 2019

Hey guys, I have a problem I can't solve and I'm hoping someone here can help. Last night I was driving my 2011 GMC Sierra 2WD 5.3L and pulled into a gas station. When I got back in the truck I turned the key to the start position but nothing happened besides the dash going black. I didn't hear the starter click and I didn't hear the fuel pump turn on.

So far here's what I've done:

Tried to jump the car, no success.
Took the battery to get tested and it's fine.
Switched the relays around to see if something else would quit working and the truck would start, but same outcome.
I jumped the two big connectors on the back of the starter and the starter turned over, but the truck never started
- it actually kept turning even with the power off and didn't stop until I disconnected the battery
I replaced the battery in the remote but this didn't fix anything. I thought it might be anti-theft related but the the light on the dash isn't on for the alarm and the truck locks and unlocks with the remote.
I connected a scanner to it and am able to see the ecm getting an ignition signal when I turn the key to start
Through the scanner I can see that the ECM recognizes that the transmission is in park/neutral

Has anyone ran into this before? Is there anything else that would prevent it from starting and cause a no crank, no fuel, no start issue that I need to check? The monitor I'm using has the ability to check basically any sensor value.

Thanks!

Edited September 11, 2019 by DanTheBetterMan

CamGTP · September 11, 2019

Check/remove and clean all your engine/frame grounds that you can find in the engine compartment.

This is where I would start.

Mikebtte · September 11, 2019

^^^^^^^^^^^^^^^^

This!

muddkatt · September 12, 2019

2 hours ago, Mikebtte said:

^^^^^^^^^^^^^^^^

This!

X2

DanTheBetterMan · September 12, 2019

All, I was finally able to figure it out. Here's what I did for anyone else that runs into this in the future:

Jumped the starter solenoid with the key in the ON position
1. This confirmed that the starter and solenoid were both working and that the truck would start
Checked for voltage at the purple wire going to the solenoid as the key was turned to the start position
1. No voltage was present
Removed STRTR relay from fuse panel and jumped the battery terminal and solenoid terminal while key was ON
1. Solenoid did not engage, leading me to believe there was a short in the wire since I was able to see that the wire went directly from the relay terminal to the starter on the wiring diagram
Checked 40A STRTR fuse and found that it was blown.
1. Replaced fuse and tried to start the truck but blew the second fuse, further confirming there was a short in the wire
Checked for resistance between the purple wire and a ground and found there was conductivity there confirming there was a short somewhere
Traced the wire from the solenoid back to the relay and discovered the harness had been rubbing on the transmission return line to the radiator next to the steering column

Once I figured out the issue I taped the wire back up and used a new harness sheath to protect it from rubbing again. I also rerouted it to avoid rubbing with the same line.

txab · September 12, 2019

diyer2 · September 12, 2019

9 minutes ago, DanTheBetterMan said:

Traced the wire from the solenoid back to the relay and discovered the harness had been rubbing on the transmission return line to the radiator next to the steering column

How did this happen?

DanTheBetterMan · September 12, 2019

1 hour ago, diyer2 said:

How did this happen?

@diyer2 the harness was routed between the power steering line and the transmissions line, which only have about 3/4" between them, and the plastic sheath that normally protects the harness was so old that it disintegrated leaving the harness susceptible to the rubbing from the transmission line. Not sure if it was routed like that from the factory, or if someone rerouted it, but it was not very smart either way.