Alright guys I’m still having trouble...I have a 2000 Silverado v6 which I recently did an Ls1 swap from a 2001 Camaro ... I used the harness and pcm from a 2001 Silverado 5.3 since it plugged right in to the fuse box under the hood ... everything seemed to go smooth all sensors plugged in with minor modifications like injector plugs ... seems like when I try to crank it doesn’t seem to do anything I had a buddy of mine reset the vats with his computer...but still no crank I hear the pump turn on and I got fuel pressure but no crank, he says it’s a ground issue to check all the grounds...can someone guide in the right direction to check how many grounds the harness should have? And what else I could check

I tried cranking it with a screwdriver on the starter and solenoid and it cranks for a quick second than it dies...on the message window inside the truck says reduced engine power after that....is there away to trouble shoot all the grounds or to known if there is enough grounds

so should I buy a brand new key and ignition switch since I don’t have access to the donor pcm’s truck

It’s used to show the security message on the cluster but after my buddy reset it with his work computer (he’s a mechanic at a local dealership) the security light no longer comes on but I still get no crank to the engine