Hworkman

I took an illegal u-turn on the hwy and I went to take off and my engine didnt. Tried to restart and it ran enough to make it a safe distance from traffic. I have had no issues with this truck. Thing to consider are the previous owner had put up some after market led's(which upon purchase I disconnected based on the quality of previous owners wiring skills),I have after market headlights, I replaced the headlight bulbs yesterday and the auto zone fella mentioned something about security when I made the purchase, and the horn sounded four times while on the hwy a couple hours previous to the break down.
I thought it may the fuel pump based on the ailment. I checked all the regular stuff. I have deduced that the electrical components are functional as I have bench tested all of them. Although, once I dropped the tank I took a reading at the harness. I saw 2.5vdc upon cranking and watched my meter slowly drop in voltage after cranking. Irregular?.?..
I also discovered that the pump relay does not open after 2sec?.?... I am missing something. Is this an anti theft or electical issue?

Hworkman

I forgot to memtion, it's a 2008 5.3l Silverado