Hiya Folks,
I'm overseas so can't work on my junk but am getting my plans in place for when I return. Currently focused on the wiring portion. I'm installing a 2007 LY6 into my Jeep YJ. I think I've got a decent handle on how to thin out the harness, consolidate the switched +12V, grounds, etc... Where I'm still scratching my head is in the integration of it all into the receiving vehicle. I've searched quite a bit and haven't really found what I'm looking for so thank you for any advice you may have.

It seems to me that I have 3 options with regards to the power distribution side of the harness. 1. Build a new (or buy) fuse/relay block. 2. Use the donor vehicles PDC, or 3. Use the receiving vehicles PDC. I see advantages and disadvantages to each. As well, I'm a bit confused as I see write ups on the fuse/relay blocks that show folks building them for ~4 relays....I just don't see how that could replace my current PDC that has 7 or the donor vehicle which has a whole lot more. I fully understand the fuse/relay blocks are specifically being designed just for engine activities but it seems to me that in addition to the blocks that are being used, one would need an additional setup to handle the other relays/fuses that handle the rest of the electrical functions on the car. I have a separate fuse block in the cab that fuses most of the non-engine systems so I understand I just need to power that up. But it appears from the wiring diagrams that the PDC, in cab Fuse block, etc... have multiple paths of integration so I'm concerned that I'll crash a ton of stuff if I don't stick with the receiving vehicles PDC.

Sorry, seems I'm rambling a bit. Bottom line is how do you recommend handling the PDC side of things? Did you build your own and populate with all the relays/fuses needed for everything (engine and non-engine related)? Did you use the donor vehicles PDC? Did you keep the existing PCD and alter it to match up with the harness?

I'm sure I'm over thinking this and really appreciate any advice any of you can give.
Cheers.

 

The fact that you are thinking of this already puts you ahead of the curve. I didn't give it any thought until I had the wiring harness torn apart. As for what to do I suggest that if your current vehicle is fuel injected then using the current power train fuse block would be the cleanest install but will definitely be a lot of splicing on the vehicle. If your vehicle currently has a carb then I would get a fuse block from an early 1990s GM vehicle and wire everything to it. It gives a nice compact install with bare minimum connections from the existing vehicle to run.

 

Thanks. I need to do a bit more looking at it to see if it would be easier to replace the current box or modify the box from a donor. The vehicle is FI but honestly, I don't see much of that in its current PCD.

Cheers.

 

Read over the diagrams from the Jeep and see how many fuses of what rating it uses, then find the wire size

If you have enough, without re-purposing alot from completely different functions, then splice the swap harness directly to the stock fuseblock. EFI cars often have sufficient fuses, sometimes relays

I deal mostly with 3rd gen Fbodys, which even in V6 form have 2 INJ fuses, a ECM fuse, emissions, fan relay, AC fuses in the stock box. More than enough for any LSx conversion. Ignoring this would be silly and have redundant circuits all over the place. Cars of the 80's often had external relays vs the 90-present integrated fuse/relay centers, so adding an extra external relay or two is simple and looks factory

Carb cars and most 4 cyl only chassis often do not have sufficient power systems for the LSx swap, so converting the swap harness to stand alone from the start is preferred

 

Same is true for all Fieros, so when I built my harness, it tied in and uses the stock fuse panel. Most 80's - 90's cars have a main harness connector (or two) for all the circuits that go back to the stock fuse panel to go through. So most of the integration work will be at these main harness connectors.

 

Thank you folks! I'm pretty tied up this week at work but am hoping to have some time this weekend to get my head around this. I'm beginning to think I may just go with something like this:
http://www.cooperindustries.com/cont...laymodule.html

This would let me just build a new PDC altogether vs. having to retrofit either the existing or donor. I don't think my existing will house enough relays as I've got a few extra serving off road lights, etc...and the Silverado (Donor) box looks to be pretty massive which doesn't bode well for an alright crammed space.

Just ideas at this point. I'll spend some time this weekend listing out all the relays and fuses I'll need and then try to decide which way to go. I appreciate all of your assistance!
Cheers.