I have an 02 or 03 LQ9/LQ4 with engine and trans on the frame. No body or anything. Hard to tell but its is one of the two but I think the wiring should be very similar if not the same. I have a slimmed down wiring harness and computer with VATS removed.I verified that all the plugs are seated properly many times. I can get the engine to crank when jumping the starter. However I'm trying to crank the engine via the wiring harness/computer. I have the (-) of the batter to the the ground terminal on the block. The (+) is connected to the large terminal on the starter. I have the "12v switch wire" and the "cranking signal" wire extended directly to the battery. I leave them disconnected. I then touch those two tires to the positive terminal with the 12v switch first(like im turning the key) then the cranking signal wire. I do have a LED(verified LED works) connected to the check engine light wire and it does not light up at all. All is get are some clicks but it does not try to turn over. Am I wiring something wrong or my suspicion is that the computer is not getting power. However I could be wrong im a novice at this. Any feedback or things to try would be great. If you need more information let me know.

Thanks

 

02 and 03 are different in the wiring.

99-02 use a similar computer while 03-07 classic use a different computer.

What's the HDW # on the PCM tear tag?