5 speed manual NV3500, with LQ4 auto V8 harness.
1. Correct me if I'm wrong, but from what I read, the clutch pedal position wire just gets depinned from F10 in the V8 harness and repinned to F11?

2. I will take the VSS connector and Back Up Lamp switch connector off the V6 harness, but are there already wires to butt splice these to in the V8 harness? Or will I need to pin and run wires myself in order for the PCM to see this data?
I have schematics showing the path and wire colors but I assumed these two wires are in the donor auto vehicles trans harness? Am I wrong?

Pics and diagrams would be appreciated.

Thanks in advance,
LINEITUP!RACING (Fbook)

 

not 100% sure... i ended up sending my harness to CurrentPerformance, where they took all the auto stuff out before i tried installing it.
the only thing they missed was that purple clutch switch wire that's literally a jumper between two harness block pins (can't remember which offhand). just check your v6 harness; i'm pretty sure it's the same spots.

 

So I answered one of my own questions so far. The VSS are the same color wires and same connector. The VSS on the auto harness is near the big round gray TCM transmission connector. So that one is easy.

Now as for the Backup Lamp Switch and where to hook that connector up into the auto harness, I'm still working on figuring that out. I know the BLS (manual) and PNP (auto) both follow same path in schematics and is Gray wire from PCM and Pink wire from fuse block to either of these switches.

And this clutch jumper thing is yet to be solved... Still hoping someone has graphic details and/or pictures for the Clutch Pedal Position (CPP) to send signal to ECM to engage starter.

 

Here are a few schematics to which I was referring..

 

What are these plugs for? More so the bottom 2 pin connector. It has a blue and green wire and was in the V6 harness but not the V8 harness.

 

The Lower plug with 2 pins is for an Electric fan option for the radiator. This started in 2005. Its wired to the PCM and can removed from the V6 harness and added to the older V8 harness of you plan on adding E-fans

The Upper plug looks like a 3 pin plug, not sure what that's for.

 

Are the Silverado and suburban engine harness the same?

 

Yes but only between 99-02 and 03-06 years. A 2003 harness will not fit a 2001 year model. You also need to match transmissions 4L60, 4L80 and manual.

 

I bought an complete running 05 suburban dbw and gonna swap into a 03 4.3 nnbs dbc. Other than the obvious like tune, headers, fuel lines, etc... is there anything else I need. I noticed there is no hole for the dbw to come through the firewall like the suburban?

 

The engine harness will work for your swap You may need 2wd or 4wd V8 engine mount brackets. You didn't post if your Silverado is 2wd or 4wd, the brackets are different between the two. I'm not sure if the brackets are the same on the SUV's and the trucks. You may find the answer in this (long) thread. The V6 brackets will not work BUT some say the Silverado V6 2wd passenger bracket will work. I replaced both with new ones so I'm not sure. After you pull the engine out of the burb you can match the brackets and part numbers with the info in this thread.