In the pictures for the 2005 Silverado 1500 you have the pin 151 stuck into two different plugs, which is correct?. Picture #7 shows pin 151 stuck into the blue middle connector and in picture #8 pin 151 is stuck into the green wire with the black stripe which is the right hand, blue & purple connector.
In picture #11 you have pin 50 stuck into the orange wire with the black stripe in the ignition harness and yet in your wire listing (page one of fourteen) you have that wire listed as being black. The black wire is also listed as the horn negative wire that you have called that out on page 2/14 as #160. The orange wire with the black stripe is (according to your INT-SL+ installation Guide) the Tach wire.