Hey guys, what are the advantages and disadvantages of having an aftermarket harness vs having a stock harness that has been modded? Im curious what you guys think and what you guys have to say.

 

Aftermarket harnesses are more costly. If you build your own you will be able to custom fit the harness and PCM location to a more exact location.

For me it was convenience. I have the skills to modify my harness, I just did not have the time. It was worth the difference in time vs cost to have one professionally done and ready to go on to my setup.

If you go with a new harness, do your research. There are some really good harness builders as sponsors here. For me the key was I wanted to be able to troubleshoot any future wiring issues and have the color of wire match the service manual.

 

Yeah the first time I swapped a motor into my car I ordered a psi harness. It wasn't cheap but wasn't overly expensive. However this time the installer I have had the skills to modify my harness. In addition, even if I had went aftermarket he would have re wrapped the harness with a better loom and wrapped it better than they come from most manufacturers. I'm extremely confident in his skill, however I wanted and still would like as many people to chime in that would like too on what their preference would be in a swap scenario. The harnesses he has used on all his swaps have his touch so I don't think it really mattered. I just saved some coin, I got the stock harness for 150 and he's only gonna charge me like 100 bucks to get it wrapped a ready for my install. I can't really complain I guess.

 

I have the factory harness that came with my low mileage pull out. It's like new and can be modded with time and patience. I have time on my side and plan to custom build a harness that is built to fit my car they way I want it, not the way someone else thinks it should be done. Yes, there are guys out there that can provide a turn key solution but they are PRICEY for what they are. Unless you are in a rush or do not have the skills, I would make one yourself. Based on what I have seen I would have to modify a purchased harness to make it fit to my liking anyway.

 

Agreed. I've also seen it done quick and dirty(unpin unused sensors from pcm and cut plugs off from old sensors, then leave abandoned wires tucked in the loom. It's not the professional way, but you can't tell). I removed the wires which takes a bit with all the tape GM uses. This make the loom less bulky.

 

Roughly 18 years ago I bought a super clean, low mileage LT1 out of a 95' Corvette and put it in my 94' Z71 truck. I still have it to this day and it runs great. The engine came with the factory ECM and harness but I couldn't find anyone that could set it up or tune it. I ended up spending $1100 on an Accel stand alone harness and computer to run everything. Nice stuff and the harness fit well but after going through that there is no way I will repeat that scenario since the factory harnesses can be modded.

 

I'm currently on the fence myself. I'll probably end up making my own tho

 

It kind of boils down to which do you want to spend more of: money or time? Both ways work.

 

No question about it, get one designed for your setup professionally made. Bp automotive has great products and awesome prices. He's a sponsor on here but just Google the name and check it out.
The first swap I did was with a reworked harness and I was very impressed.. However, this time I went with a brand new harness, and I was blown away.