magnumP5's RX-7 Build Thread

It's good to hear I'm not the only one!

I've spent countless hours looking over the Wiring Diagram in the FSM and although I'm getting a hang of understanding them there are still a lot of questions I have. Fortunately, I've been in contact with C. Ludwig from Ludwig Motorsports (he's on here somewhere) and he's been helping me out a lot. Basically, I want to remove every wire, connector, fuse, relay, etc. that is no longer being used in the car. Basically this lets me almost completely (I need to save the wiper control and temperature sendor wires) remove the emissions and control harness, but that's the easy part. What I've now come to understand as the "front" and "engine" harnesses are almost completely intertwined. Most of the engine harness will stay as it's basically just the main power loom . The front harness (what I called the "main" harness in my last post) has all sorts of crap that needs to be weeded out. I'm discussing with C. Ludwig just exactly what can be removed and what should stay. For example, I may want to keep the stock ECU 12V fixed and 12V switched sources available to use with the Haltech. The stock tachometer signal wire is another. However, the stock wires are 22 years-old now so maybe they should be replaced. The other source of confusion is exactly what his harness contains. I know it'll have all the appropriate injector and coil/ignitors plugs and wires but what about the power and ground I mentioned previously? The fuel pump and its relays will need all new wiring as well because their sole signal source is the stock ECU.

Anyhow, I did remove some more crap last night. I ended up pulling the bumper cover off to expose some wires and to remove the silencer for the air pump. I'll try to remove the emissions harness today and snap some pictures just so you guys can see how empty the engine bay is getting. I really need to get rid of the power steering crap as that's covering a lot of the wires I need to get to.

Still looking for a turbo motor though :(
 
Made some progress last night. I'm still pondering what to do with wires but I decided to tackle what I know I could remove. Passenger's side of the engine bay is getting kind of empty. Everywhere you see a random bolt or two is where some bracket used to be.

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For those who are scared by wiring (and you should be) these next few pictures may be hard to bear...

Below is the emissions harness completely stripped of its grimey, sticky, protective coverings hanging over the passenger's front fender. This was not a fun task at all.

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This is what I removed:

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After that I had to pull several interior pieces apart and pull up the carpet to access the ECU and the connection points between the emissions and front harnesses. As much as I hate working under dashes this was surprisingly easy without seats, LOL. Full emissions harness removed and shown below. Everything on the right was connected to something in the engine bay. The two yellow connectors at the top (near the neat foil shielding) are the ECU plugs and the yellow and gold connectors to the far left are the interfaces between the emissions and front harnesses.

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The yellow wire that seems separated from the rest is the temperature sender wire for the dash temperature gauge. This and the wiper wires, which are hidden in the mess, are the only wires that will remain when I'm done.
 
Ahhh! It actually hurt to look at those pictures.

Just be sure to check continuity on the stuff your keeping before re-wrapping.
 
Yay wiring!

Looking good, brotha. You give me confidence in my wiring. Keep up the good work and updates.
 
Ha, I'm glad I'm not the only one scared by wiring (and I'm an engineer, too!). I swear it's all voodoo, black magic or whatever...
Ahhh! It actually hurt to look at those pictures.

Just be sure to check continuity on the stuff your keeping before re-wrapping.
This is going to be a must because I've found the Wiring Diagram in the FSM to be inaccurate already. Maybe it's because 1989 was the first year of the S5 RX-7 but it's like they hacked apart a S4 ('86-'88) FSM, keeping what they thought they could, and then added the S5 ('89-'91 in the US) later. Two noteable errors I've found so far include the wiring to the wiper motor (incorrect plug listed) and the theft-deterrence system, which is actually quoted as being both integral to the CPU and a separate module. The former is true of S5's while the latter is S4's I believe.

So I separated the emissions harness last night. I actually didn't end up cutting a single wire even though my electricians toolbox is very limited. I found that a very small flathead screwdriver, like those used to repair glasses, is a perfect tool to fit into the connectors to lift the tabs holding the spades in place. Pictured below is the new, trimmed-down emissions harness (left) versus what was removed (right):

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The one thing I'm slightly nervous about is the FSM shows the "Passive Shoulder Belt" interfacing with the emissions harness and utilizing one of its ground points, which I've now removed. I knew this ahead of time but removed it anyway because the seatbelt system has another, dedicated ground that does not involve the emissions harness so I assumed everything would be okay. Also, because I'll likely be using 5-point harnesses I'm less inclined to care if the stock restraint system works...

The only other wiring stuff I did isn't noticeable in pictures - so there aren't any! The A/C system consists of two primary circuits that interface with the front harness: AC1 and AC2. I removed AC1 last night, which consists of the refrigerant pressure sensor, A/C main relay and magnetic clutch (this connects to the "pump"). I'll tackle AC2 tonight, which is behind the glovebox and I think it's just a span of wire, two plugs and a thermoswitch. Since I don't want to remove the dash I figured I'd just unplug what I can...

After that the P/S mechanics finally came out. Not as straightforward as I thought but it wasn't too difficult. The engine bay is getting more and more spacious and at last I have full access to the front and engine harnesses, which run along the driver's side.

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I really need to start weighing all the crap I've removed...
 
LOL, that's alot of left-over wire! Watch out for homeless guys hanging outside your garage... waiting to steal it for the copper. :)
 
Are you going to paint the engine bay while you're in there or just clean it up?

ps- thanks for the tip about the wiring connections. ;)
 
Good lord. You have pulled almost as many wires out as I have in my FC. Granted mine is set up for track b**** detail with a gutted interior and a sweet suspension setup. Send me a PM if you have ANY issues bro. I am THE wiring guru at work, and I built my engine harness for my FC (For a megasquirt ECU) so I know this stuff pretty well. Plus I got acess to mitchell on demand schematics. Sweet!!!!
 
LOL, that's alot of left-over wire! Watch out for homeless guys hanging outside your garage... waiting to steal it for the copper. :)
Homeless guys aside, now you're just giving me ideas. What's the going rate for copper now???
Are you going to paint the engine bay while you're in there or just clean it up?

ps- thanks for the tip about the wiring connections. ;)
I'm probably just going to clean it up now. I know I talked about painting it but I'm not sure I want to deal with the hassle of either removing everything or masking everything off. How did you clean yours prior to painting?

I really should take a picture of that screwdriver. It's like 1.5" long with a neon green grip and a shaft that's maybe .0625" in diameter.
 
I just cleaned it with Purple Power and paper towels, then sprayed everything down with brake cleaner and more paper towels. The masking honestly only took about an hour, if that. And I think it's worth it. The spray paint is holding up pretty well, actually. Of course you have to be careful not to scratch it, but that goes true with the OEM paint in the bay as well. I would love to see your bay semi-gloss black with just the rotary in there and the essentials. I know it's purely cosmetic so not really up your ally, but how often do you get the chance to paint your bay?

I've got a small screwdriver set from Radio Shack, but a pic wouldn't hurt of that screw driver.
 
Copper is going for quite a bit right now. Roughly $3.80 a pound.
 
Yeah, especially compared to the .60$ per pound I got for aluminum cans during earth week, which is double...
 
Good lord. You have pulled almost as many wires out as I have in my FC. Granted mine is set up for track b**** detail with a gutted interior and a sweet suspension setup. Send me a PM if you have ANY issues bro. I am THE wiring guru at work, and I built my engine harness for my FC (For a megasquirt ECU) so I know this stuff pretty well. Plus I got acess to mitchell on demand schematics. Sweet!!!!
I plan on running a Haltech Spring RE with a custom harness but I'll definitely keep you in mind. What series FC do you have? Just in case I have any general electrical system questions. I would be interested to know the "proper" way to run the power and ground wires after relocating the battery.

Evan, I think I'll clean my engine bay first then decide what to paint. If I do, while black would look great I'm inclined to side with Marc in that it would be nearly impossible to track down leaks and such. That being said if I do repaint it'll likely stay red or in the extreme case go white (because light red = pink).

Copper is going for quite a bit right now. Roughly $3.80 a pound.
Awesome, so I have like $3.80 sitting on my garage floor! This does bring up a valid point though; what is the best way to trash/recycle/whatever the parts I'm leaving off? Things like the P/S and A/C system...
 
Depending on the material, recycling centers may take some of that. That's where my dad takes a lot of his left over car parts. They pay pretty well.
 
There are a lot of people looking for hvac and all sorts of other oem parts on other rx7 forums..

I'm interested in this wiring. I will be doing the same!
 

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