I've seen a few references to people whom might offer thinned wiring harnesses - but it seems to have been a while. Who's the best option? Looking to ideally move both the immobilized and fuse box to behind the passenger airbag panel, and run as simple a harness as possible ...

We have done several wiring harnesses at Atlanta Speedwerks for our builds. It saves a lot of weight and relocating things to the trans tunnel makes life much easier.

It is a very labor intensive process and doesn't come cheap.

Step 1 is removing the entire wiring harness. Are you up to that challenge?

Mark Foley has a mil spec build for 1200 for this

When I built my spec Boxster, I pulled literally every single unnecessary wire, fuse, relay and even cut down the fuse box. I saved everything I pulled and weighed it; saved like like 6lbs. For probably 50 hours of work. IMO it's not worth it at all to do.

Thanks for going through the trouble of weighing and reporting this to all of us.

I did the easy stuff and stopped - this makes me think it's not worth getting too involved!

We pulled about 20lbs.

I'm not really worried about the weight, more interested in simplifying the system so that potential issues could be troubleshooted much more easily

To do this is very time consuming, as you don't want to introduce more issues than you simplify out. To do it right you not only want to clip the wire, but you want to pull the pins out of the connectors, remove fuse blocks, unused relays, etc. I think I ended up its like 7-8 fuses total in the passenger compartment. Then there are all sorts of mid harness splices which makes things complex too. On the bright side, when I was done I could basically identify every system just by the wire color!

I got about 25 lbs out of my wiring harness and had about a week of part time work into it. My advice is to leave it in the car, work on sections at a time so you can start the car and verify you didn't screw up. Get a copy of the wring diagrams so you can trace it out and be methodical about labeling things you cut. Others who I have seen do it and dive head first in and just start cutting end up spending a whole bunch of time diagnosing why the car wont start.

Or just leave the wire and lose some driver weight?

That wasnt enough for me. My car was built heavy by the previous owner and in my quest to get down to weight I had to start in on the things that take a lot of work and have small gains. I was pleasantly surprised I was able to take out as much weight as I did.

You also end up with a much more serviceable car. Under my dash was a rats nest of wires. Now it is clean tidy and serviceable, which make me feel much better there isn't loose wires that could potentially cause issues.

Hey Todd - I’ve got a wiring harness from a ‘97 parts car that I’m going to thin out for an SPB, already removed from the car. I know you guys have done a ton of these. Do you have a schematic or spreadsheet that shows all wires that can be removed?

thanks,
Tim

hell there's no way I could remove 25#'s of driver weight in a week , unless I sold the car :-)

Unfortunately nothing easily sharable. We have large format schematic drawings we've marked up, many many pages. It's about a 10 hour job once the harness is out.