Engine will not crank, no spark or fuel pump after engine swap?

2003 GMC SIERRA

100,000 MILES • 5.3L

JOHN'S HEADACHE

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Just removed blown up 6.0l ls and replaced with a 5.3l ls from a 2007 Chevrolet Tahoe now engine wont crank, no spark or fuel pump. Used the original harness and computer.

May 2, 2023 at 6:01 PM

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Please double check the main engine ground to the wiring harness, here is the location so you can see what I am talking about. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.

Images (Click to enlarge)

May 3, 2023 at 10:16 AM