Truck stalled while leaving parking lot. What may have caused this?

[Doubeleive]

Well if it is running ok I would think it is either electrical or fuel.
just turning wheels isn't going to do much, try taking it on a spirited drive, gas/brake/swerve/hard braking

 

[mikez71]

Might try a new run/crank relay since power was lost. Possible bad ignition switch if not the relay?

 

[testdepth]

Well if it is running ok I would think it is either electrical or fuel.
just turning wheels isn't going to do much, try taking it on a spirited drive, gas/brake/swerve/hard braking

I was thinking electrical which is why I was turning the wheels to see if a wire was rubbing. Wife was turning left when this happened. In the morning I'll pop the hood and start looking at wires to see if there is anything obvious.

 

[testdepth]

No codes or check engine light this morning. Battery is at 12.39 volts and when the engine is running it's 14.78 volts. With engine off I tested from battery positive to engine block ground, firewall ground and ECM case. All read exact battery voltage 12.39. I started the engine and under the hood I tugged and moved every cable I could find and the engine never missed a beat. I then test drove it trying to get it to fail by hard stops, pushed and pulled on ignition key, beat the steering column, beat the dash, multiple turns left and right, jerking the truck violently left and right, uturns and round a bout circles. It never missed a beat and runs like new. I don't know what to think??

@Doubeleive do you happen to know where the computer ground wire is attached on this 6.2 motor?

 

[Fless]

No codes or check engine light this morning. Battery is at 12.39 volts and when the engine is running it's 14.78 volts. With engine off I tested from battery positive to engine block ground, firewall ground and ECM case. All read exact battery voltage 12.39.

If you were attempting a voltage drop test, the circuit needs to be loaded; meaning the engine should be cranked while doing the measurement, to test the current capability of the cables and connections. Straight voltage measurements with little or no load don't load the circuit and show only continuity.

 

[mikez71]

As intermittent as it is, and with power cutting out to your gauges, I have to think it might be something like a bad fuse box that was mentioned by John H..

But swapping the run/crank relay is easy to try, if you haven't done it already..

 

[Doubeleive]

ecm is mounted to the frame/body in the engine bay, don't know where the BCM main ground is on these.
there have been some rare reports of water intrusion to the ecm connections on these.