lsxponcho

Hey Guys,

Hopefully someone can help me out, as i fear I may be in trouble here. I have a complete 4.8/4l80 combo/harness/ecm pulled from an 07 Chevy Express, dropped into my 06 RCSB. This is a gen 3 LR4. I also have the tac module, pedal, column and bcm taken from the van before I scrapped it. The van came with the truck as a package deal which is why this swap took place.

The truck originally was a 4.3/5 speed. Everything has gone ok with installing it so far, with the exception of a couple of plugs that don't match up. I was initially worried as the engine position in the van vs the how the harness is spread around, and plug locations, that it may have been largely different than the truck harness version. All seems ok that way though, and I think it lays in the there like it should.



The van has a couple of connectors that the truck harness wouldn't have had, i.e. brake switch, heater box plug, etc. Also the van ran a clutch fan, where as the truck has electric fans. The harness for the fans is part of the truck body harness, so i'm not sure if the vans ecm will trigger them or not. I may be forgetting a few things. Anyways I've taken some pics for visual aid. Hopefully someone can help me id these, or know the pinout info.

First are the bulk of the questions around the fuse box.


Here is a pic of two plugs that are left not terminated from the truck harness, which both sit under the fuse box normally. The white plug has 8 wires (with spares), and the small black one is a 2 wire.



This is the donor's harness plugs that don't match up.
- Firstly the engine connector doesn't fit the fuse box. Its just slightly different, and longer. I have to find one from a truck and re-pin. oh well.
-The small white plug fits fine in the fuse box.
- The wide black connector next to the engine plug that I labelled "body plug" On the van it was terminated to a matching plug on the drivers side inner fender. Maybe it needs to be re-wired to match the white plug on the truck?
-down in the bottom right corner is a 2 wire plug that has a factory cap from the van. Maybe should match the 2 wire plug from the truck? The connector is slightly different so they don't technically fit.
-Next to that the donor harness had the brake light switch on it, where as the truck already has it in its other wiring. I'm thinking this is not a big deal


Here is the trucks original negative cable. This "module" for lack of a better word, does not have a plug to go in it. I believe it was part of the 4.3's harness. It is not part of the negative cable itself, it just sits there. I'm wondering if its even needed, or if i can just toss it.


The mass air has a different style connector than the 4.3 mass air unit. The van has a weird air intake, but I plan on getting a cold air intake...just need the v8 mass air meter.

01WS6/tamu

iTrader: (36)

The easiest thing you need to do for your sanity is find a harness from a 06 3/4 ton truck with a 6.0. The functional differences between the van harness and the truck will drive you nuts trying to get it all straightened out. Don't get me wrong it's doable but you need a through understanding of wiring and how it controls the various items and all data or the gm book. It's just way to many mods to instruct through a internet post.
With the van pcm you can use HPT to enable the pressure sensor and cooling fan controls so your factory cooling fans can be controlled correctly. You will need to land 2 wires for high and low fan speed at the pcm so it can control the oem relay's.

lsxponcho

I totally agree. I'll be the first to admit i'm not a wiring guy. I've been searching pinout info, which is pretty easy for the trucks. Vans on the other hand are hard to find. The years have weird changes, and there are enough differences between the truck and van, that i'm more that happy to cut my losses and purchase a truck version so its plug and play. Even though this is a budget build, any issues avoided afterwards is money well spent.

My next issue is finding another good donor harness. Salvage guys want to sell harness's with engines, and not just the harness itself. I plan on making a trip to pick n pull in the next little while, and hopefully find a good candidate. The only down side with that is 99.9% of the trucks around here are 4x4, so I will have unneeded harness. 6.0L trucks are hard to come by, but worse case scenario I should be able to find another 4.8, or 5.3 harness, and just re-wire it to the 4l80 I think.

If I were to find a 6.0L, I would hopefully grab the pcm also. Plans will be for a 6.0 down the road anyways. This may be a dumb question, but I wonder if the 4.8 would run okay un-tuned on a 6.0L pcm? After I freshened it up, I installed an LQ9 cam, ported the heads heads, and bought 1-3/4 long tubes. It will have good dual exhaust afterwards also.

brandon6.0

iTrader: (26)

y not just pull the whole harness back out and look at lt1swap.com at there modified standalone harness pinouts. Thin just remove the crap u don't want and make that harness work.

I wanna say the black small harness is not used. The ground cable connector is on the newer platforms. my 2000 model doesn't have it so I'm sure u could remove it. I think the black body pigtail is your stuff like ign, bcm etc. Best bet is to go standalone and reroute the harness and clean things up.

O yea my cousin was swapping a ls in an older truck like yours. He has a psi conversion harness for the swap. He had it on a 5.3/80e. PM me if u might be interested in it. I could ask if he wants to sell it. He is doing away with the truck.

lsxponcho

I found out the black module is the battery generator control module, so i think its needed. I thought about going stand alone, but right now I would prefer to have it working as stock. At least that way i have a baseline if any issues creep up after the fact once I get it running.

1FastBrick

iTrader: (17)

You can reuse the factory PCM you have and get it flashed with V8 calibration.

You will need the BGCM thingy on the negative cable.

I would have no problem grabbing a 4x4 harness just a few extra plugs you can remove or tie up out of the way.

lsxponcho

I sold the V6 pcm with the old motor, but I have the proper pcm for the 4.8/4l80 combo from the van...just gotta get it vin flashed. The budget minded me was just wondering if it would live fine on a 6.0 pcm (If I found one with matching harness) with the few mods it has until an lq4 or lq9 is found, just to save on the flashing, etc

DrX

iTrader: (7)

Do the pins/colors on the white connector match up to these? Do they match the colors on the black connector from the van?

Do the wires on the black van connector match up to the highlighted PCM pins in the attached pinout chart.

lsxponcho

I will check tonight, and let you know, thanks!

DrX

iTrader: (7)

Did the van have the generator/battery control module?