Monday, July 27, 2015

He just smiled and gave me a Vegemite sandwich

I think it goes without saying, but big things are happening here at the Iron Hydroxide HQ. Grace is alive. She runs and even drives. I took her around the block last night. I have internet. This is evident because I am blogging again. And roomate Vaughn is smoking a salmon and t-bone steaks for a celebration dinner. 

Unfortunately my phone has a terrible mic, so all my videos sound like they were shot in a pineapple under the sea, but you get an idea of what the tractory turbo beast sounds like. There is still a ton to be done before she's road worthy, but she runs quite well for a totally un-tuned setup. I didn't dare get too crazy on my test drive since she's full of parts and who knows what other surprises, but it was good to see her progress from a rolling money pit into a driving money pit.

The neighbors must have noticed my working frenzy over the past few weeks and been drawn to it because last week I had 5 different neighbors approach me while I was working on the car to chat with me about it. I've spoken with the next door mechanic, Don, on previous occasions so we chatted about his health since he'd been having some scares with his diabetes but is doing great now. Don and all the other friendly neighbors aren't the only ones who have noticed though. I got a nice nastygram in the mail from an un-named sender. Don was appalled when I told him about it.

Stupid mechanic...

I've been promising a blog post about wiring for about two months now, so I guess it's a little late, but better late than never I suppose. Wiring is one of those parts of the build that is ironically dreaded and overlooked at the same time, more so than any other system on the car. It's like car guys feel that if they ignore it, it will go away. Of course this feeling is understandable, considering the massive amounts of wiring in modern cars. But I'm here to tell you something that if you are a gearhead you'll probably disagree with (If you aren't, hi, welcome to Iron Hydroxide. I'm Jesse, and I have an addiction).  Wiring is fun. 

Yep, you read that right, wiring is fun. I guess I should put some qualifiers on that. Tracking down a slow current drain in a modern car, or trying to figure out why your Jetta dies when you turn on the blinker is not fun. But rewiring a classic car from from the ground up is fun. If you spend the money (and you'll do a lot of that) to get good supplies and components, its a relatively easy and relaxing job. The yoga poses required to run wires under the dash aren't always awesome, but it's no worse than wrestling a greasy transmission into submission.

At this point I've only wired the functions necessary to run the engine but left the chassis un-wired.  I had a few rules for myself when wiring this car. First, there would be no splices in the wires. This was difficult because the terminals you crimp to the ends of sensor wires are extremely varied and can be incredibly hard to find. It's not something that is stocked by auto parts stores or even auto wiring shops. Eventually I contacted Ron Francis Wiring, the vendor that sold me my chassis wiring kit because they also sell factory replacement wiring harnesses. They were incredibly helpful in helping me find the terminals for my crank sensor and throttle position sensor and sent them to me for a very reasonable price.

Ford crank sensor terminal
Ford throttle position sensor terminal
Second, I insisted that all my wires be larger than they needed to be, and grounded better than they needed to be. This meant running 1 gauge battery cables, both positive and negative, from the battery box in the rear to the front of the vehicle. The Ron Francis Express wiring kit I used also provided wires that exceed their necessary size. I got the Express wiring kit from them and have been very happy with it so far.

Third, I refused to solder any connections on the chassis or engine wiring harnesses. I would crimp an  heat shrink every connection. I've mentioned this previously but this required me to buy another tool which as I'm sure you've noticed, I really hate can't stop doing. I inherited this affliction from my dad, Pa Davis. I think he's a compulsive tool buyer. He'll see a four foot long set of channel locks and think "I'm sure I need that for something". I'm not sure he ever does, but I always ended up finding a use for the four foot channel locks. In this case I had to buy a cable crimper. I suppose I could have found a stereo or lowrider shop to crimp my battery cables for me, but I didn't want to rely on a shop to complete this job, and why would I pass up an opportunity to buy another tool. The upside is that I've used this crimper way more than I thought I would and it only cost $35.

And fourth, I decided that all my harness wrap would be braided style wire sheathing with heat shrink protecting the ends. I had used this before on a project at school, but when I built my computer, the power supply had this style of wire sheathing and I fell in love with it all over again because of how tidy it made the computer case look.

My overkill mindset carried over into the battery, where I ended up buying a 750 CCA battery for a low compression 4 cylinder. I suppose this battery is a little large for the Falcon, and a bit of extra weight, but with the 1 gauge cables it spins the engine at 350 RPM while cranking (normal is 200-250) and I won't have to worry about it dying on me.

I also went with at 130 amp alternator from a Taurus. This is a common upgrade done to 1980s fords, as they often came with weak 60 amp alternators. Some have suggested I add a larger charging wire since this is only an 8 gauge wire on the alternator. I have the supplies and will probably switch to a 4 gauge charging wire.

It can be a bit difficult to show any meaningful pictures of wiring harnesses, so I'll just post photos and captions. That's what the kids are doing on the instagrams right?  (yes I'm on instagram too) @gearandlightning #metamucil #hotmixtape #hashbrownsofinstagram #followme #veganbacon #glutenfree

GM intake temp sensor and wires
83 lb/hr injectors with EV6 connectors
Coil connector 
Firewall pass-thru

Boost control solenoid with incorrect wire colors (black is a +12v wire and should be red)
Boost control solenoid corrected
DIY Autotune relay board before wiring
DIY Autotune relay board after wiring (under dash, driver's side)
I wish I could tell you that after wiring, I turned the key and it fired up instantly. Such was not the case. after blowing a few fuses, I found that my ignition coils which I thought were LS1 type coils were actually LS2 type coils. In all honesty I did not realize that there was a difference, but there is. They use the same connector, but the wire positions in the connector are flipped. This meant I had to de-pin and re-pin the coil connectors.

After correcting the coil wiring, I still could not get spark. I had a few days of near insanity trying to track down the issue, but eventually realized that I had misunderstood the labeling of the printed circuit boards in the ECU and relay board. If you are a Megaquirt user, read on. If not skip ahead or prepare yourself for this:

S1, S2, S3, S4 on the relay board DO NOT correspond with spr1, spr4, spr3 and spr4 on the ECU as I had assumed. I had my ignition trigger wiring on s2 and s3 (relay board).

Relay board/ECU location/DB37 pin
S1 = IAC1A = pin 29
S2 = IAC1B = pin 27
S3 = IAC2A = pin 25
S4 = IAC2B = pin 31

I had jumpers from pad1 to spr2 and pad3 to spr3. There are two problems with this when using the relay board. the relay cable does not have wires in pin locations 3,4,5,6. This is where spr1, spr2, spr3, and spr4 are located. The second problem is that the spr outputs on the relay board are hidden from view, and to not have any terminals attached to them.

So in order to fix this, I kept my wiring harness the same, but removed all the jumpers that had previously connected

js0 > iac1a
js1 > iac1b
js2 > iac2a
js2 > iac2b

and then put jumpers from
pad1 > IAC1B
pad2 > IAC2A

Previous board setup
Current board setup

Ok dear reader, you can come back now. So yes, Grace is finally mobile. I'll register her next month. But as you can see, she's far from finished. It's just starting to get good, so stay tuned.


  1. Well done sir. Video without the sound of the Millennium Falcon landing behind you please. Kidding, nice work.

  2. I've read every other post, but I can't read about wiring...