Routing the harness thru the cab

[michael bustamante]

So I bit the bullet and bought a harness. But I have a couple of questions. First off what are you guys doing to route the harness into the cab? Are you cutting a hole in the floor are you running it through the firewall? I'm at a loss there. I'll attach a picture to show The grommet that came with the harness. Second I cannot find the purple starter wire on this harness anywhere. What's going on with that? PSI harness

[mongocanfly]

You will reuse your old starter wires...they are Independent of the LS harness...
On the grommet I've been drilling the grommet hole above the driver side valve cover...then I run all my under hood wires thru the grommet..you can run it anywhere you feel comfortable with and have clearance on both sides of the firewall...
It's a gripe of mine about the psi harness...theres to much wire to easily fit under the dash, and not enough wire to reach under the seat...which is where I want mine...would be nice if it was a ft shorter or a ft longer

[michael bustamante]

Yeah I was looking at that too. It's not enough to go under the seat at all so I guess I'm going to have to mount the computer under the dash somewhere. But on my OEM harness it had a purple wire on it that I just tapped into. so now I just want my old wire directly to the starter like usual?

[mongocanfly]

Correct ..all you need is the wire from the switch to the solenoid...and it should run thru whatever safety switch you have

[michael bustamante]

Ok cool man thank you.

[nsb29]

I went with BP automotive which was long enough to go under the seat Was very happy with their harness it came with high pressure transducer for the AC as well as a signal wire for the speedometer some of the Others I inquired about did not

[mongocanfly]

I'm thinking ill use a BP on my AD when I get to it...

[Pontitruck]

Originally Posted by nsb29

I went with BP automotive which was long enough to go under the seat Was very happy with their harness it came with high pressure transducer for the AC as well as a signal wire for the speedometer some of the Others I inquired about did not

This is what I used as well and i am in the process of tucking it and the TAC harness/module away as well.

[Ramiro0727]

Originally Posted by michael bustamante

So I bit the bullet and bought a harness. But I have a couple of questions. First off what are you guys doing to route the harness into the cab? Are you cutting a hole in the floor are you running it through the firewall? I'm at a loss there. I'll attach a picture to show The grommet that came with the harness. Second I cannot find the purple starter wire on this harness anywhere. What's going on with that? PSI harness

Here is where I mounted ECM and where the harness goes into the engine compartment. The harness was PSI also.

Thanks,
Ramiro

[nsb29]

Originally Posted by Ramiro0727

Here is where I mounted ECM and where the harness goes into the engine compartment. The harness was PSI also.

Thanks,
Ramiro

No A/C ?

[LS short box]

I like to hide as much wiring as I can.
I mounted the ecm behind the glove box. No ac. Had to notch the glove box a bit to make room for the ecm. Fuel pump and fan relays next to the ecm. Screwed the OBD port and fuse block to the heater box. Ran the engine harness low enough so you can't see it when you are in the truck. You can just barely see the grommet/harness near the left cylinder head with the hood up.

[Ramiro0727]

Originally Posted by nsb29

No A/C ?

nsb29,

Its a ac cab. AC will come later. Trying to get the running on the road first.


Ramiro

[Ramiro0727]

Here is a picture where the harness comes out to the engine compartment.

Ramiro

[LS short box]

If you have the harness length available I would pull it down so the other wire bundles aren't seen. Here's a pic of mine. I use Howell harnesses and there is just enough length to hide the wire bundles.
Good luck with your swap.

[nsb29]

Originally Posted by Ramiro0727

nsb29,

Its a ac cab. AC will come later. Trying to get the running on the road first.


Ramiro

The reason I ask was it appears your ECM and relays would be in the way of the AC

[michael bustamante]

Originally Posted by Ramiro0727

Here is where I mounted ECM and where the harness goes into the engine compartment. The harness was PSI also.

Thanks,
Ramiro

I was thinking about routing there too..

[michael bustamante]

Originally Posted by LS short box

If you have the harness length available I would pull it down so the other wire bundles aren't seen. Here's a pic of mine. I use Howell harnesses and there is just enough length to hide the wire bundles.
Good luck with your swap.

Damn that's clean... All I see is that pink wire on the firewall... Them are good engine covers!

[Ramiro0727]

Originally Posted by nsb29

The reason I ask was it appears your ECM and relays would be in the way of the AC

nsb29 when we are ready to install the AC. If there are in the way i will move them to a different spot.

Thanks,
Ramiro

[Ramiro0727]

Originally Posted by LS short box

If you have the harness length available I would pull it down so the other wire bundles aren't seen. Here's a pic of mine. I use Howell harnesses and there is just enough length to hide the wire bundles.
Good luck with your swap.

look great LS short box.

Ramiro

[derotoreut]

I brought mine into the cab through the floor and mounted the PCM and fuse/relay box under the passenger seat. You can see it in my 70 K10 build thread.


I drilled a hole for either 1-1/2" or 1-3/4" grommet (can't remember now)



PCM and fuse/relay box goes under passenger seat. I was going to keep the OBD2 port there too, but I decided to move it under the dash.



I used Blazer tilt brackets so I would have access to the PCM if needed.