Need Help - Wiring Doomsday

[NYX]

Hi

We got a AC Cobra Chevy 350 Small block. Upon the removal of the dashboard I got slammed in the face with a wiring nightmare.



As you can see most of the wires are the same colour.

So starting at a singular point I now need to get this mess sorted as it has been clearly proven that my first attempt at just tidying up the wires have left the Cobra in a "Not starting" mood.

Distributor
What colour wires should there be and what should they be connected to?

[Bill Bess]

Get your test light, start with ignition system and then do each section (dash lights, blower switches etc. by group). Check that all grounds are good, replace if necesary and then tie them off with tie-wraps to be neat.
Have fun, take pictures and notes of what you do and mark the wires with tape to identify what you found.
It ain't that bad. Bill

[Tommy]

The wiring in my car was not up to my standards when I bought it, so I rewired it from front to back the way I thought it should be done. I realize that is not what you want to do, but you might borrow part of the concept. First, figure out what kind of ignition system you have and what it needs in the way of power and grounds. For example, you likely have a coil that receives power from a wire that is energized when the ignition switch is ON. You may also have a wire with switched +12v power to the distributor. After you figure out what your ignition system requires, look for the wires that likely provide that power and check them with a multimeter. If they don't have power when the ignition switch is on, check for power at the output terminal of the switch. If you have power at the switch but no power at the ignition components, either the wire is broken/shorted, or the wire connected to the switch is not the same wire as the one connected to your ignition.

Troubleshooting wiring can be a time consuming process. That is one of the reasons I just removed the old wiring and installed new stuff.

[Ron61]

I did mostly what Tommy did.The wiring that came with my car was all white with just small numbers on it at spaces and they would rub off after you touched them a few times. I went to NAPA and bought a whole box of rolls of wiring of different sizes and colors and as I wired each thing I drew a schematic of it and put it into a loose leaf notebook. It took a while but was well worth it as I could just get the notebook out and look for what I wanted and there was the color of the wire and where and how I had ran it. It took more time to do it that way but it saved a lot of time later on when I needed to find a blown fuse or something.

Ron

[NYX]

Hi guys thanks for all the answers - the best bet is to scrap what is there and start fresh.

therefore I am starting at the engine bay with the distributor. i need to know what wires are needed to be connected to it and what guage should they be.

please bear in mind that I am completely clueless with this so every little detail in your explanation is helpful.

according to my research i have found a wiring diagram for a electronic distributor. it should have 2 wires, one 12v switched 14 gauge and then a tach. Is this correct? currently I have a ground from the distributor and 6 wires

[mreid]

Study this manual from Painless for their universal harness. It will answer your questions about routing, gauge, color, and layout. You can then duplicate the sections you need.

http://static.summitracing.com/globa...0501manual.pdf

[NYX]

thank you mr mreid - i hope this solves my nightmares and sleepless nights

[Buzz]

I also have a Cobra with a bowtie motor and like you, I was faced with a similar mess when I first looked behind the dash. In fact, that was one of the major factors in my decision to disassemble and rebuild the entire car with new parts and wiring.

One of the best parts of that decision was the purchase of a completely new wiring harness from my car's manufacturer, Unique Motorcars. I got a complete harness made for Unique by Prodesign Systems and for a complete novice at automotive electrical wiring, installation was a snap - far easier and safer than trying to muddle through the mess of wiring that I'd inherited.

Here's a schematic diagram I drew up a few years ago when I was doing some troubleshooting. Its based on the actual colors of the wires used and is drawn from a combination my own tracing and the schematics in the Prodesign manual.
Hope this helps

[Tommy]

Originally Posted by NYX

please bear in mind that I am completely clueless with this so every little detail in your explanation is helpful.

If you don't know much about the fundamentals of electricity and wiring, I second the suggestion to get a pre-made wiring harness that comes with instructions. Another alternative is to have someone who does understand hot rod wiring fix what you have. A regular car repair guy won't do. You need someone who has worked on hot rods with custom wiring. .... Wiring is one of those things like brakes, steering and fuel lines that needs to be done right for the car to be safe.

If you want to do this yourself, post some pictures of your distributor and anything that is wired to it. That will help us see what kind of system you have.

[Murky781]

NYX..I've been where you are, but with a well marked, new harness. problems but no clue how to chase them down. I went out and bought a great book..Automotive wiring and electrical systems. it's a workbench book and i found it at Barnes and Nobel for $25. great basic beginners book. Head out to Sears and buy a Fluke multimeter for around 75 and then give yourself a few hours of reading time and you will be on your way. this book gives you the basics, plus the tricks needs to learn quickly. well worth the investment for owning a car that shakes loose electrical components so efficiently! Then ask everyone on here and you'll get thru it. Mark everything and get a notebook for shortcuts and write down EVERYTHING you do, because you won't remember it tomorrow! I learned that the hard way. Good luck and welcome to the club!

[Tommy]

If you live near a Harbor Freight store, you can pick up a multimeter for less than $5.

[Bill Bess]

I agree with the suggestions above, buy a new complete wiring harness for you cobra. The looms are easy to lay out, wires are marked where they go and it should be farely easy to redo a cobra. Checkout HAYWIRE, they do the kits for Hurricane.
Bill

[NYX]

alright currently we have to work with what we have got since the new harness will only arrive in 3 weeks time. we do need the cobra to run.

so far we have done the following and replaced a few things:

the electronic distributor blew the module which we replaced.
the coil tested still in working order.
starter is wired correctly.

yet still the conra now turns over but still does not start

[Tommy]

NYX,
There may be people on this forum who know more than me and have figured out what kind of ignition system you have, but I still need more info. For example, on the engine originally in my old Corvette, power from the ignition switch went through the ballast resistor before ending up at the coil. A separate wire powered the coil during cranking to bypass the ballast resistor during starts. The engine currently in my Corvette has an electronic distributor with the coil built into it. It receives power from a single wire that is powered when the ignition switch is on. ... My Cobra has an MSD system that receives power from the ignition switch before sending power on to the coil and distributor. Another car I have has an entirely different ignition setup.

Without a picture or a more complete description of your ignition system, it's hard to offer advice that is more than a WAG.

[NYX]

thanks guys, we have actually decided to send the cobra in and have some professionals run diagnostics on it and get it sorted out.

i will you guys updated on the outcome