Wiring Harness question

[Chrysis]

I've been doing all the reading and searching I can, but I'm still not sure what wiring harness and PCM I need for my 2005 L33, and if I need anything other than a pedal for the drive by wire? Will an LS harness work, or will I need something specific to the L33?

I Have the 5.3 L33 block, and an 4l60E transmission hoping to find a home in a 69 GMC stepper.

If I'm blind and missed an obvious link, just point me to it and chastise me, I can take it =)

Thanks in advance!

[6.0 1955]

Did you get a harness and computer withe the motor? 05 would be drive by wire. Do you want to run a drive by wire setup? If so you will need the TAC module, wiring, and pedal from a compatible vehicle. There's many pin out listings for each years harness to do your own.
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[Chrysis]

No, unfortunately I did not get the harness or PCM. I'm fine with the DBW setup, as long as I know what parts I need to get and can figure out the cheapest way to source them. I've read that some drive by wire setups didn't use a TAC module, so I wanted to verify before I start digging.

So the connectors on the harness from any LS will be the same, it is just the pin outs that will need to be changed to make it suit this engine? I assume with the exception of if it had an 4l80 or 4l60? Or is there a separate wiring harness for the transmission controls.

Again, thanks!

[BR3W CITY]

Originally Posted by Chrysis

No, unfortunately I did not get the harness or PCM. I'm fine with the DBW setup, as long as I know what parts I need to get and can figure out the cheapest way to source them. I've read that some drive by wire setups didn't use a TAC module, so I wanted to verify before I start digging.

So the connectors on the harness from any LS will be the same, it is just the pin outs that will need to be changed to make it suit this engine? I assume with the exception of if it had an 4l80 or 4l60? Or is there a separate wiring harness for the transmission controls.

Again, thanks!

the 05 will use a tac module, and will need to be matched with the correct pedal. iirc the 05's used the big plastic pedal assembly style. You'll need the harnesses for the tac and pedal as well.

There is a different transmission harness for the 4l80s. If you get an pcm that did not come out of a 4l80e equipped vehicle your tuner will need to do a segment swap. The 80's use an additional vss.
Not all ls's will be the same, as early ones didn't have ANY provision for DBW wiring, car harnessess have shorter runs than the truck and van harnesses.

take a look at lt1swap.com in their wiring section they have a ton of references on ecm pinouts and wiring differences, it will give you a better idea of some of the similarities.

IMO paying for a wiring harness/fuse box is the smartest money you can spend on a swap, tied somewhat with getting a real (read: dyno) tune. I paid like 550-600 for mine, but nice lengths of high-grade loomed, terminated, easily labeled wires with instructions and good customer support was well worth the money. I even had a couple "bumps" in the road of switching out things like my alternator style AFTER ordering the harness; the guys at fuelinjectionconnection sent me all the pigtails I needed for free and drew up some notes on correcting it. They had no obligation to do so, but did it happily.

[chuckmc8]

"IMO paying for a wiring harness/fuse box is the smartest money you can spend on a swap"

I agree completely. Lots of guys have done their own harnesses with success and the engine fired right up; but for those whose didn't, it led to lots of frustration and hassle.

I bought my 5.3 and 4l60 with the harness and computer already modified. I saved money in other ways, such as I fabbed the mounts, did the fuel system simply, yah yah yah

I set it in, fired it up and just enjoy it. No hassle at all- I'm certainly not saying that folks shouldn't do their own wiring mods, it just wasn't for me

[Chrysis]

Thanks everyone. I'm headed in the right direction again! Well, I'm headed in a direction...time will tell if it was the right one.

My funds for the project comes from my toy budget.... which is extremely low. =) So, while I have fully taken the sage advice of purchasing a complete finished harness to heart, they cost more than my engine and transmission together. So the way of pain and frustration is the path I tread. =) Hopefully, now it will be less painful.

Off to read of pin outs and stripping wire looms.

[old yelr]

I've read that some drive by wire setups didn't use a TAC module, so I wanted to verify before I start digging.


I believe that beginning in 2007 or 2008 the TAC module functions were taken over by the E38 PCM and the TAC module was eliminated.

[Chrysis]

Ok, the Engine is a 2005 B vin 5.3 L33 . That would make it a GEN III correct? I've found someone who has a 2007 harness and ECM (e67). That will not work due to the differences in the 24tooth or 58 tooth reluctor, correct? Or can that be addressed?

Thanks!

[BR3W CITY]

don't put yourself through that, just find a genIII blue/green ecm and matching tac/pedal.

[Jon01]

What he said.
Find the correct components and either buy a chopped harness or have someone do it for you.
I use Bill @ BPAutomotive, send him your harness and $250 and you'll get a nicely cut harness, full fuse/relay box and everything's all labelled/ready to rock.
His customer support is killer too, I emailed him one Friday night at 9:30, had a personal call 5 minutes later. It doesn't get any better than that!

[Chrysis]

Thanks, I just wanted to make sure the gen 4 harness and PCM wouldn't work, or be easily converted.

can anyone tell me off hand what ECM/PCM the L33 had?

Thanks again!

Chryss