Need a little help on 5.3 wiring

[hubdawg]

Put a running driving 2004 Tahoe 5.3 in my 72 K5 from a 72 K20 donor. The removal was not as clean as I'd like and I lost some of the prior connections. Here is a picture of my wiring and any help filling in the blanks as to what goes where would be appreciated. Also does anybody make a inspection cover for a 5.3 to a TH350 or do I have to fab one.

[TrybalRage]

lt1swap.com if you're not aware of that site already.

Orange typically is constant 12v. The white on the right side could be tachometer signal.

[Wgesnerjr]

Devote a lot of time on LT1swap.com. The information is there but you have to dig. I learned that EVERY link in a paragraph leads to something else. Explore stuff you think has nothing to do with your swap. Info is everywhere.

It's not set up like a traditional website with tabs or a navigation pane on the left. Just pages with writing that have RED links to other pages.

Still, great info. Without it I would have never been able to do my swap.

Brendan also does PCM reprogramming. I sent mine to him and worked right off the bat.

[hubdawg]

Thanks I'll dig into that site some more. Anybody on the inspection shield ? Also where are you running your wire bundle through on the firewall and what type of grommet. The prior vehicle had everything mounted on the fender and I'm thinking more sanitary in the glove box area

[Wgesnerjr]

I used the 4L60E so i don't know about the inspection cover. For my 85, I used the stock fuse block for a lot of the standard wires. There were plenty of other additional access holes I reused for other items.

[bigmoe]

Originally Posted by hubdawg

Thanks I'll dig into that site some more. Anybody on the inspection shield ? Also where are you running your wire bundle through on the firewall and what type of grommet. The prior vehicle had everything mounted on the fender and I'm thinking more sanitary in the glove box area

Are you re-working a stock wiring harness? If so it's a lot easier to route the wires as originally done which would put your ECM on the fender again. If you want to run the wires through the firewall to mount the ECM inside the cab then the harness will take even more disassembly, reworking and lengthening to get the wires going in that direction. As for your relays, fuses etc., you can build your own per LT1swap.com or you can buy them premade from Current Performance or BP Automotive. Myself I sent my stock harness out to someone and had it reworked and ready to mount.

[bigmoe]

These work good for large bundles through the firewall. Made by Seals-it.

[mongocanfly]

I did my firewall hole behind the drivers side head..that way it wont interfere with hvac stuff...
Itll be a fairly large hole to get all the wiring and connectors thru...I used psi harness,,it comes with the grommet....you might contact one of the harness places...they may sell the grommets..

Heres a few ...
https://www.bp-automotive.com/produc...ewall-grommet/

https://www.speartech.com/product_p/grommet.htm