Engine and Dash Wire Harness Rebuild Project 68' 1600

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ct06033
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Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by ct06033 »

So, this all started with me and my 68' 1600 getting stranded 350 miles from home with a bad alternator and voltage regulator. After replacing both and making it home, all kinds of other gremlins have been poping up. First, I lost all lights connected to the Headlight switch then the car would continue running with the ignition off. This all came to a head with my regulator going out again. (i have not checked the alternator yet, so hopefully that is still fine but I will be having it rebuilt since it was used when I got it)

Image
This also happened.

After having these issues come and go with no apperant root cause and seeing the rats nest under my dash, I decided to go all in. Wires were cut and taped together, unprotected connections just hanging there waiting to short, and years of other owners tinkering have left their toll.

After looking into all the options for repairing or replacing my wire harness, I have decided to go all in and build my own. My reasons for going this route are such:
  • OEM replacements are expensive and still have the same inherent weaknesses of my current harness.
    Butchering a universal harness will be no easier and with added complexity due to the non standard wiring in our cars.
    I want to modernize certain circuits and integrate others.
    I am a masochist.
So, the goals for this project are:
  • Upgrade all wires using high grade replacements and increase gauges where applicable.
    Incorporate some of the enhancements from this site as well as an electric fan circuit, Electric Fuel pump, and modern radio.
    Document as much as possible for the site (modern vendors, pricing, challenges, and solutions). With the exception of one other thread, I do not belive this has been well documented.
I do have some decisions to make such as whether to run both an Ammeter and Voltmeter or just run a voltmeter (I am not confident I can integrate it into the cluster as well as others on the site). Also, how much of the circuit I want to modernize as that would increase the complexity of the build and I do not claim to be an EE.

My progress so far:

One more note: I am trying my hardest to not remove the dashboard as I live in an apartment so there is only so much I can take apart without causing issues. I do keep the car under cover, but it seems doable without going through the extra pain.

Image
At this point, I removed the fuse box, passenger side harness that enters the engine bay, and the center console. I do not plan on putting the new fuse box in the glove box Re: my previous note making it too difficult to route the new wires properly. I will be leaving myself enough slack to route properly should I choose to do so in the future.

Also of note, it is practically impossible to get to the clock with the dash in. I will re-install the light (and circuit) but I will not attempt to reconnect the clock. I also found a possible suspect as one of the leads to the clock was pinched in the frame and rubbed bare. I will also re-route the aux line (map light, cigerette lighter) through the fuse box as I think a clean connection will be better than whatever splice was done from the factory.

Image
On to the Driver's side. Nothing much to note here other than more dodgy wiring and some of the upper lights were hard to remove. Also, this is going to be a real pain putting back in.

Image
The harness out of the car. I have it laid out so its in the basic layout as it would be in the car if you were sitting in the drivers seat.

Hopefully this is of some interest to some of you. Be patient, I will be updating as I go. Next update will be the engine harness. Then i can make some measurements, order parts and start building the new one.
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by notoptoy »

Ambitious project for sure, I assume you are referring to Curtis's posts on the wiring harnesses. That's a great resource and I would read it through thoroughly. In addition there are several others with loads of experience that can help. I would certainly lean liberally on these resources as needed. Good luck and thanks for documenting your journey
"When all else fails, force prevails!" Ummm, we're gonna need a bigger hammer here.

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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by Curtis »

I will tell you this, you are in for a lot of work if you try to rebuild the harness in the car. Remove the center console to make it easier. I would take the seats loose so you can remove them when working.
66 stroker, almost done.
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ct06033
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by ct06033 »

Curtis wrote:I will tell you this, you are in for a lot of work if you try to rebuild the harness in the car. Remove the center console to make it easier. I would take the seats loose so you can remove them when working.
Absolutely I am, but with the car not charging like it is, and other gremlins, I think it is the way to go as it is very unreliable at the moment. Removing the center console is a must to get access to the main harness but I did not need to remove the seats. I just popped them all the way back and was able to squeeze in at an angle (not my first rodeo upside down under the dash of a car).

Your previous thread is playing a huge part in enabling me to find suppliers and get started. I am hoping to fill in some of the blanks with my thread so someone else may have an easier time starting a project like this. I do like your suggestion of separating out the modern components into a seperate harness and will most likely mimic this to an extent.

On further inspection, it looks like the harness was rebuilt or refreshed at some point since most of the connectors are in pretty good shape aside from being dirty and a handful of spades look to be original. Also, the connectors seem to be a mix of older and newer style plugs. I am not sure if this is normal, or the result of someone's work.
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by Curtis »

When I built my first harness I did it with the harness out of the car. I untaped it and copied each wire and it took me a lot of hours building and thinking about changes. I overbuilt it.

Now I have breadboards and finished a 68 dash harness about 98% today and have a second one about 70% built. Easier to build at least two at a time. Putting a modern fuse box on it.

I wouldn't even attempt to do it in the car.
66 stroker, almost done.
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ct06033
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by ct06033 »

Curtis wrote:I wouldn't even attempt to do it in the car.
I think there may be some confusion. I'm not attempting to build the harness while it is still in the car. I'm... Not even sure how one would go about doing that!
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by Curtis »

ct06033 wrote:
Curtis wrote:I wouldn't even attempt to do it in the car.
I think there may be some confusion. I'm not attempting to build the harness while it is still in the car. I'm... Not even sure how one would go about doing that!
Okay, your pictures made it appear like your were attempting it. Even out of the car and untaped the harness is a PITA to figure out.
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ct06033
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by ct06033 »

Okay! I had some time tonight so I went out and removed the engine bay harness. It is definitely in worse shape as the years and heat have not been kind.
Image

I ended up cutting the heat shielded alternator cable as i was too lazy to get to the alternator tonight which, being on the drivers side, requires a removing lots of parts to get to.

Otherwise, it was pretty straight forward although those little metal clips are delicate! I felt like one or two of them were going to give out on me as I bent them back to get the harness out.

Nothing else worth mentioning other than the giant clump of wire on the right which go to the electric fan. The PO couldnt be bothered to splice the wires to length so its just a tangled mess. I also found out the relay is temperature controlled (makes sense) so it will be really difficult to route it how I would like and may just keep the relay in the engine bay and just clean up the wires.

I also ended up doing some initial shopping tonight. I am still figuring out what gauges I will be using for wire. I will also be getting a new battery cable even though the current one is in pretty good shape. Having a red negative cable is really bugging me!

I bought all the plugs and bullet connectors from vintage connections. Originally, i was just going to get the kits, but its much cheaper to purchase each plug individually and purchase a kit for the bullets.

Total bill: $119 with shipping.

From Amazon, I bought some missing tools and other parts. I will be using Silicon sleeved wire on all parts of the harness near the engine. This stuff isnt cheap but +200c operating temp!!! Will not have to worry again about melted wires.

Shopping list:

Auto adjusting Wire Stripper
High Temp Teflon Coated Glass Fiber 12gauge wire (for alternator)
Nylon insulated wire spades (these seemed better quality than Vintage connections outside of their color and I am not going for exact restoration YMMV)
Heat shrink tubing (make sure to get adhesive lined ones like I didnt... have to reorder)
Hella 8-way fuse box (has a semi sealed cover and each fuse is its own circuit which will allow for more flexibility than other options)
Hella 4 mini relay box (to match with the fuse box)
Heat Gun
Solder Wire (found me some lead free stuff. Harder to melt but im not a fan of toxic things)
Heat Shield Sleeve (this may be overkill with the type of wire i am using but can never be too safe!)
Silicon Wire (various colors and gauges for temp sensor, alternator, and starter harness)

Total bill: $160

I still have a few more items to get such as the relays and tape but thats all for my update tonight!
Last edited by ct06033 on Fri Oct 28, 2016 6:17 pm, edited 1 time in total.
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by Curtis »

ct06033 wrote: High Temp 12gauge wire (for alt, the cloth braided one)
Cloth braided? Somethings not right.

Should be one 10 gauge wire and some 18 gauge wires.
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ct06033
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by ct06033 »

Curtis wrote:
ct06033 wrote: High Temp 12gauge wire (for alt, the cloth braided one)
Cloth braided? Somethings not right.

Should be one 10 gauge wire and some 18 gauge wires.
Sorry, Teflon Coated Glass Fiber. Is it a 10 gauge? I was just going by eye. I had some 12 gauge laying around and it seemed to match up pretty close. Since I already ordered it, I will see what it looks like when it comes in and order 10 gauge if needed.
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by Curtis »

It looks like quite the mess. Sins of previous owners.
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by AltxF4 »

Previous email owners and wiring harness hacks are some of my biggest pet peeves with cars! It will definitely be worth the work! I have had several electrical fires in my old VW's due to hacked up wire harnesses.
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by ct06033 »

AltxF4 wrote:Previous email owners and wiring harness hacks are some of my biggest pet peeves with cars! It will definitely be worth the work! I have had several electrical fires in my old VW's due to hacked up wire harnesses.
Tell me about it! I always proscribe to "if you are going to do it, do it right". Hence instead of just trying to fix the symptoms, im starting from scratch.

My washer fluid pump is MIA on my car... I only drive in fair weather and my wipers dont work worth a crap anyway (still looking for an adequate fix) but it is still kind of a bummer. At least i found their circuit.

I also found out why my flashers dont work. I can only guess at some point the original flasher burned out and they jerry rigged the hazards flasher to the turn signals, rendering the hazard switch useless. I am going to set things back the proper way and cross my fingers there isnt an issue with the hazard switch.

Another trip to Amazon... Shopping list below:

Tesa PN 51608 Interior Harness Tape

This is fleece lined for noise reduction. I am also hoping it will reduce friction as the harness just kind of flaps around loose under the dash. I debated using the same tape for inside and outside but I kind of like the idea that this will result in one less rattle in the car.

Tessa PN 51036 Heat Resistant Engine Harness Tape

Like the name says, it can withstand heat to 150c. The listing was actually for 50126 but the seller says he ships the newer version 51036. I only mention this because this listing was much cheaper.

Scotch (or 3M) Super 33+ Vinyl Electrical Tape

Need a way to protect splices within the harness. While Heat shrink can protect a two wire splice easily, I am not sure how well it will work with a 3-way splice. Ill do some testing once everything is here but I bought this as a backup. Some people on here with more experience than I can probably add their take on this.

4 relays for the harness

Turn Signal Flasher x2 + Bracket

CEC EF32RLNP also has a ground so when I upgrade lights to LED, it will still be compatible. Decided to just upgrade the turn signal flasher since I need a Hazard flasher as well. The one in the car is original but it always bugged me how slow it went.

Total Spend: $127

That is all for now. This project is getting pretty expensive but at least all I have left to purchase is wire!!
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by fj20spl311 »

You are going to need an order from http://vintageconnections.com/
I have fount it easiest to just go to the price tab to order.

Don't forget to order the crimping tool - RTL Crimping Tool
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ct06033
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Re: Engine and Dash Wire Harness Rebuild Project 68' 1600

Post by ct06033 »

fj20spl311 wrote:You are going to need an order from http://vintageconnections.com/
I have fount it easiest to just go to the price tab to order.

Don't forget to order the crimping tool - RTL Crimping Tool
yep, already ordered in my first batch.

i didn't list out everything but the crimping tool was definitely on the list.
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