Monday, May 2, 2022

How to identify connectors

I really should have done a better job of labeling the wiring harness when I was taking it out of the donor. I did label some things, but not nearly enough. And as I am doing the wire diet a couple of years later, I have no bloody idea what some of these things connect to. Here's how I am figuring it out.

First, I choose the next connector I want to work on. I make note of its color, number of terminals, gender, and general configuration. This one is pretty simple, because it only has two pins.
Then I pull back any loom or sheathing near the connector and make note of the colors (main and stripe) on each wire. Bear in mind that these wires spent a decade and a half in the engine bay of a car, so they are definitely dirty, and may also be discolored or faded. More than once, I have gotten the colors wrong, and have had to go back and look again to find the correct color.

Then I use all of that information to make a little sketch of the connector, and note down its characteristics. There's a pretty well-defined language for this in the documentation.

This is a female connector, so it gets a single border, and the pins are numbered from left to right. Each possible color is given a consistent letter (or two). I have this written down as green with a pink stripe, and brown with a yellow stripe.

It turned out this was incorrect, which caused confusion, but that's what I have noted here.
I do know which harness I am working on, so I can take a look at this chart to make some guesses about which connector it might be, and note those down.
Then I flip through about 150 pages of wiring diagrams, looking for a connector that matches my description. Here, my pinky points to a matching sketch, and my index finger points to more detail on the wiring diagram.

This is the second time through the book, though. I said previously that I got the colors on one of the wires as green and pink (GP) - but I didn't find that, so I looked again and saw that it was in face green and orange (GOr).
So there we go. It's connector number F79, the connector for the air conditioning pressure switch. I labeled it and moved on to the next connector down the chain.

The kit car won't have A/C, so later on, I will go back and remove these wires from the harness.
Here's the current status of the harness. The bits on the table to the left of the blue tape roll have been identified and labeled; the stuff on the floor and to the right of the tape still need to be gone through.

Once I have it all labeled, I can continue the diet.

How to Wire Diet

There's a lot of wire in a modern production car. The wire diet is a very useful (but also very time and labor intensive) part of a kit car build. Here's how I am doing mine.

There are a lot of features that were in the donor car that I won't be using in the kit, so I am just tripping wire out that is related to those feature. In this example, anti-lock brakes. Nope, no driver aids in the kit car. This is the connector that plugged into the ABS unit, and I don't wat it flopping around in the kit, so it's time to diet it.

Pick a wire attached to the plug. It doesn't matter too much which one you choose, because they are all coming out eventually. Cut the wire close to the plug.
And then chase it back through the rat's nest of wire. The harness went to all corners of the car, so it's possible that a single wire could be fifteen or twenty feet long, piled in with a few hundred others. 

Oddly, this reminded me a lot of chasing network cables through a crowded wiring closet. I guess my time in IT has some real-world applications after all.

When you get to the other end of the wire, cut it off there, too.

Then, you can bundle it all up and chuck it into the box of wire that you have already pulled out.
Repeat as necessary, until you've removed every wire from that plug. Chuck the plug into the box as well.

Then identify and diet the next unneeded plug.

You may note a couple of things in the background of this pic - first, my hands are filthy; and second, the orange bucket half-full of trash. Both of these result from having to remove a lot of electric tape and wire loom from the bundled harness. The adhesive on the tape, after years in the donor car, turns to goo that gets all over everything and is challenging to wash off.

Wednesday, April 27, 2022


Minor progress this week. Other hobbies and events have intruded heavily into my shop time, unfortunately.

But I did manage to make some progress in dieting the wiring harness. It's a very small example, but this is the dash clock out of the donor car. I won't be needing that, so I traced and cut out the wiring for that. I'm still working on identifying what everything is.

I also started working on the parking brake handle. This one is out of the donor car. It used to have a plastic / faux leather cover on it, but it was so scratched, worn, and peeling that it didn't make sense to keep that part. I'm going to have to find a way to wrap it with leather so it's not quite so ugly, but that's a problem for later.

What I was able to do, though, is cut down the mounting tabs on the bottom, and get some steel welded to the bottom for mounting in the car. This helps move it down and back a bit, so it will be less in the way while driving.

Here's what it looks like sitting on the tunnel. The heavy cables are the push-pull tables that actually operate the transmission at the back of the car. I did get a little bit of work done in making the clamps for the ends (the silver ferrules), but I need to put more thought and effort into building that.

Both the parking brake and the shift lever have solutions in the kit, but I have opted not to use them, because I like my way better.

Friday, March 25, 2022

Wire Diet II - Diet Harder

If you remember my previous posts about wire diet, that was just the harness for the top of the engine - this is the diet for the main part of the car. There's a lot more to it, and of course not all of it is labeled, so there's a lot to get through. This lump of wire weighs maybe 30 pounds at a guess.
The first key is to go through and identify things - and if they are not needed for the kit, to go through, wire by wire, and remove them. This module, for example, had unknown function until I googled the part number and found out that it's the cruise control computer. No cruise control in the kit, so the box got removed and all the individual wires run back and cut out.
All of these are airbag wires, which connected to the airbag computer in the dash of the donor. This system is mostly discrete from the main harness, so it was easier to pull out these cables as assemblies rather than wire by wire.

I pulled out a good chunk in my first pass, but there's still a lot to do. And I also will need to identify all the wires from this harness where they connect to the engine harness, because there will be a bunch of wires I can remove there to match things I cut out of the engine harness already. Then the fun of splicing it all together can begin. Or just building my own, I haven't really decided yet.

Wednesday, March 16, 2022

Driveline work

Only one photo in today's update, because everything I worked on was in the rear of the car.

First, I got the axles in, connecting the outputs of the transmission to the rear hubs. Of course, this meant I had to unbolt all the links that connected the knuckle assembly, and just last week I bolted a bunch of heavy stuff to it. I ended up using my engine hoist as a kind of skyhook so I didn't have to wrangle all the weight myself.

As I was putting it all back together, I also assembled and installed the rear coilovers, and went through to install a bunch of spacers on all of the bolts connecting all of the rear suspension members to the rear knuckle and to the frame. And there are kind of a lot of them - each side has two trailing links, three lateral links, and a coilover.

Last but not least, I installed the shock tower brace that ties the rear end of the frame together above the transmission, adding rigidity to the rear portion of the frame.

It feels like good work got done this week. I'm excited to see what happens next.

Wednesday, March 9, 2022

A collection of smaller tasks

I took care of a few smaller tasks this weekend - little things that were not super critical, but definitely needed to be done.

First up, I bolted in this support for the back of the driver's seat. The seat bottom will bolt to brackets on the floor; this supports and constrains the upright back section. I need to take it back out again, of course, because I need to paint the steel angle it's bolted to.

I also finished installing the brake discs and calipers. Big ol' vented rotors, front and rear, and Cadillac Brembos to provide squeeze.
In the rear, same setup, except for the addition of a Wilwood e-brake.

The donor car, like most passenger cars, had more braking up front. The kit, being rear-engined, needs more balanced brakes, so the big discs and 4-pot calipers on all four corners will help, particularly since the brakes are unboosted. There will be a proportioning valve in the hydraulic system to tune the balance if needed.

And the shift cables showed up today, so I had to get them installed. They go from the tail end of the transmission up to the shift lever - past and around the engine. I need to fab up a mount for the clamps on the tunnel, but that shouldn't be hard.

I'm thinking axles and rear suspension might be next.

Wednesday, March 2, 2022

Back to it, and it feels good.

Well, even though I haven't been posting lately, I haven't been completely off the car project. I did do a little bit of recreational research, by going flying with my uncle. This gave me the chance to try out a headset which I may end up using for an in-car intercom. It should give me good hearing protection, allow conversation with the passenger, and also give me audio from my phone for navigation.

But as far as actual work on the car, this weekend I got the shift linkage installed again, and hooked up some push-pull cables to measure for length.

These cables are way longer than I need, because I am using a different shifter than the kit specifies. This should give me better shifting, with a shorter, more direct run.

The cables go up over the engine block, then down through the firewall and into the tunnel, where they will hook up to the shift lever. Once I got them routed, I marked them, removed them from the car, and measured them, and then I submitted an RFQ to have custom cables made.

I also reinstalled the upper portion of the rear firewall, and got a few holes set up so that important things can go through it - fuel filler, fuel tank vent, shift cables and electrics. The fuel tank is in and bolted down, too, and I finished bolting down the seat rails and anti-submarine bracket for the driver's seat. 

There's also another portion of the firewall which will install forward of the fuel tank, but I'm not quite ready for that - which in turn prevents me from completely nailing down the seat mounting. But I did put the seat in and sit in it for a while today.
I was going to call it a day there, but the header wrap tape I had ordered showed up, so I wrapped the two pieces of the exhaust that I had not yet wrapped. This is the passenger side header, which I wrapped with 1" wide tape. The other components (driver-side header, crosspipe, and up-pipe) all got 2" tape, but the tight bends and branching pipes on this one made it easier to wrap it with the narrow stuff. 
Then I mocked up all the exhaust pieces. Nothing is tight here, just assembled as a mockup. Like most things in this project, it will probable all come off again before it's final.
Turbo goes here.