It is 3 pics overlayed. I don’t have a wide angle lens to fully capture the mess so I had to scab 3 pics together…
Should have used a tripod.
How much more wiring do you have to do?
PS has an align and stitch feature.
all that wiring makes my stomach hurt, wish i knew how to do that sorta stuff and read wiring diagrams
keep it uP
Seriously, how DID you learn how to do this? I dont fully understand how a wiring diagram translates into the car. Any chance you could post a vid of you describing how one circuit is completed in the car so we can all get a visual of how it looks in the car and how it looks on paper? Make sense?
You’re going to school for engineering? :lol:
what is to video?
line = wire
goes from 1 spot to another.
match point a with point b.
repeat hundreds of times until your brain hurts.
not trying to downplay the complexity of rewiring an entire car, but asking for a vid of how to read a wiring diagram is :touchy:
When I rewired my corrado I just looked at the wiring diagram until it made sense.
What program did you use to draw up that wiring diagram?
Yeah. It’s not easy to explain, but I’ll try and summarize it as briefly as possible. Trying to pay forward all the help other people have given me…
Let’s simply imagine that were talking about a light.
Obviously any electrical circuit needs a complete loop. From battery positive to the light back to battery negative. Very very simple.
In a car, the negative “wire” from the light to the battery is really the whole chassis. so The power flows out of the battery, through a wire, into the light, out of the light and into the frame, out of the frame back into the negative terminal of the battery.
Obviously, you want a switch to control your light. A switch basically completes or breaks a wire’s continuity. The switch can be anywhere in the circuit, before or after the bulb. An easy way to think about electricity is like water flowing through a pipe. It doesn’t matter if you plug the pipe at the beginning or end, water is still going to stop flowing. Equating electrical systems to fluid systems is the easiest way to think about circuits.
I could type so much more, but I’ll just walk you through a semi-simple circuit on my diagram…
The reverse light switch:
We’ll start at the positive battery terminal. The battery is a big red block.
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electricity flows out of the battery in the yellow wire. (the green wire that breaks off almost immediately connects to the alternator, which recharges the battery) The yellow wire goes through a 50 amp fuse (for safety’s sake).
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after electricity flows out of the fuse it either continues on into the ignition switch through the YELLOW wire (Represented as a matrix of lines and circles)… or onto other things that need a CONSTANT power through the PURPLE wire, since they aren’t connected to a switch (we’ll talk more about that purple wire later… forget it for now)
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When the ignition switch is turned to IGN (or ON) power flows out of the switch through the red wire into the fuse panel. (If you want me to explain how the switch diagram itself works, let me know… but I think it’s pretty self explanatory)
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Now we’re at the fuse block. Nearly every fuse in your car operates at one of three states. These states are controlled by your ignition switch. The three states are BAT, ACC, IGN. Depending on what position the key is in decides whether the fuse will have + 12v or 0v. Remember that purple wire from earlier? That’s what’s providing the BAT state to the fuse block. Any fuse that’s a BAT fuse is ALWAYS +12v. The Yellow wire provides +12v to the fuse block when the key is ON.
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Find the headlight fuse in the fuse block. See how on the left hand side it says IG? That means that the fuse is an IGN fuse and will receive +12v when the key is ON. This is what we want for our reverse lights. Follow the pink wire out of the fuse block. It ultimately ends at the reverse light switch. This switch is located on the transmission and is either OPEN or CLOSED, meaning it allows current to pass or it doesn’t. When the car is shifted into reverse it CLOSES the switch and allows current to pass through it. (the light blue wire that branches off the pink wire feeds the headlight relays. Relays will be another lesson)
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So now current flows out of the switch through the blue wire and into the back up light. Pretty basic.
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the current flows through the light, out the other side and into the gray wire which is bolted to the chassis. This symbol:
means that a wire is “grounded”, meaning it’s bolted to the chassis. Your chassis acts like one giant wire and every wire with that symbol on the end is electrically connected together. -
The electrons then flow out of the chassis into the battery through the gray wire attaching it to the chassis.
You have now completed a simple automotive circuit. One thing to note. In a diagram like this, everything that crosses doesn’t connect unless there is a little blue circle at the joint.
It’s done in autocad. When you rewired it did you make your own fuse block or buy one?
Newman, great job breaking it down! I learned a ton when putting the computer controlled LT1 into the '55 Chevy, mostly by doing a lot of staring at the wiring diagram. I found the most difficult thing was knowing when to use a relay, what size fuse, what size wire, etc. If you get a chance…maybe expand on this?
This is going to be awd, right?
The first step is finding out how many amps your component draws (ref manufacturer specs, use a clamp on multimeter if you can power the component with a battery, etc)
Once you know your current draw, the rest is easy. I usually take these charts w/ a grain of salt, but reference the “CU Max enclosed Amps”
http://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity
Choose a wire that exceeds your current draw.
Choose a fuse that breaks at an amperage slightly less than the maximum ampacity of the wire.
When to use a relay is a LITTLE bit trickier. There are 2 reasons why you would want to use a relay. Location and current draw.
The former is a bit simpler. If you have a a current draw that requires a 12GA wire, running that from the battery to a switch in the car back to the component can become a pain. 12GA wire is pretty big and hard to work with. If instead you can locate a relay box near the battery or power distribution block, then you only need to run a small 18 ga wire from the relay coil to your switch.
The latter reason to use a relay is if you don’t want a ton of current flowing through your switch. In the case of headlights, usually a headlight switch isn’t designed to flow the 10+ amps required to run the lights, so you use a relay. This allows the switch to only see a few miliamps [flowing from+12v through the switch through the relay coil to ground]. And the contactor in the relay sees the 10+ Amps (flowing from +12v through the relay through the light, into ground).
I had an issue w/ my front dif so it’s actually going to be 3wd.
Who says an ME can’t play with the sparkies? Nice job so far, although I don’t envy untangling that mess of spaghetti. 
Used the factory ECU. Most of the wiring from the firewall back was retained, but everything forward was completely redone. I just grabbed power from empty locations on the ECU to power new components and the standalone.
See, I was able to use about 50% of my factory EFI harness because I bought a plug and play ECU. I rewired my entire chassis from more or less scratch.
Couldn’t you just have hacked off the ECU plug and wired in a fying lead harness?
Lame bro you should just make it rwd
Great progress Newman. Did you add any “Flare” to your interior or did you keep the OEM guages, HVAC, dome light, etc…?
I am 3/4 through my LED conversion in my car. I am making my own 194 size bulbs for my guages. So far I retrofitted my HVAC, Door Switches, Hazard Switch, and Fog Switch as those are the only lit bezels I plan on re-using after my interior is done. If anyone has any comments about my project shoot me a PM. Don’t cloud this thread. I will be posting a Build thread covering the whole car sometime this year.
(Preview for anyone interested: http://mr2oc.com/showthread.php?t=375146)
FYI to everyone - while it is a major headache at times people really should not be afraid to tackle wiring projects big or small. The more you work with it the easier it becomes to you naturally as with anything. If anyone has any questions, even after Newman broke it down very; very well, then ask. You should not do something just because you are not familiar with it…right? That is kind of the point of this Forum.