Custom Harness
 

Today I'm going to start "designing" my harness. First I'll do everything that attaches to the MS1, then I'll work on IGN/Charging/Starter circuit, then lighting. I think.

I'll probably adjust fire as needed to make sure everything is correct. I'm going to basically follow the OEM wire diagram, only cut out the fat. So there should be no electrical fires :ohnoes:

Anyways I'll be posting my progress, and wiring diagrams here for review from the smart people.

I understand some of them may migrate over here soon:rolleyes:

If Lars can do it, you can do it.

I gutted the wiring harness on my car. It is a lot of work, but everything still works great, and it eliminated so damn much clutter under the hood and under the dash. Having a factory wiring diagram is the way to go. It takes a lot of guess work out of it.

Well the harness is going to be built from the ground up. Only using connectors and some relays/fuses from the old harness.

I have a rough daigram for the engine harness. Finishing up the MS1 to engine harness now. Then will start wiring up all the wires inside the bay. Should look fantastic. I have pics, just no time to post them.

Maybe 10% done. Very early work.

https://www.miataforumz.com/attachme...ine=1314733615

https://www.miataforumz.com/attachme...ine=1314733615

[IMG]http://img89.imageshack.us/img89/7523/94309149.jpg[/IMG]

Coming along nicely. Are you planning to put a power adder on the car, or are you building a hot N/A?

Turbo eventually. Looking for 220-240whp. Goal is fun weekend street car. Maybe turn boost way down and do an autocross here and there.

couldn't spring for heat shrink?

Are you talking about the harness in the pic above? Yes it is heat shrinked, under the e-tape. I'm extra cautions, don't want to do this twice. You won't see that part when I'm done anyways, so dont' care if it's ugly. :D

where are you getting your wires btw?

Eh I ended up just grabbing them from Lowes. They had some on sale. I don't care about color to be honest. I really just need to know the colors at the connector and MS to do any sort of testing.

you can use labels, you can pick up a sheet of 500 white and/or clear vinyl labels from office-depot/max/staples for something between 10-30$ depending on your quality preference. this makes things much cheaper, as you can buy large bulk amounts of 2-3 color wires and stick with that. Just gotta be meticulous with your labeling (and it sounds like you are meticulous with a lot of things anyway!).

We used it on my Data Acquistion project and it does wonders (although our issue was more related to sensor location than wire identification).

Ah good idea, i've just but cutting small pieces of painters tape and folding it over the wire. Forgot someone might actually make those hah.

I ditched the connector shown in the picture above (the circle-ish one). It was not up to my standards. Seemed very sketchy. I'm going a little bit different route, but it means I have to do a lot of the work over :/ But I'd rather do it right the first time.

hehe, had to make some corrections to my comment. home-depot doesn't sell envelope labels lol.

Yea, I would change to some good ol' standardized connectors. Digi-key is a good place to start, but it can be overwhelming. DB-xx style cables for ECUs are a good place to start but they can be VERY tricky to solder depending on the quality you get.

https://www.miataforumz.com/attachme...ine=1314988006
^A bitch. especially with solid core wiring mixed in with the conduit style wires.

You can spend a bit more money and get something easier...pinning maybe a good alternative, but sometimes it can require a special tool.

Wired up the COPs. Still need to connect it to the actual harness. Will do that tomorrow.
https://www.miataforumz.com/attachme...ine=1316137965

https://www.miataforumz.com/attachme...ine=1316137965

that looks great, but I wish there was high-temp electrical tape for those.

Yea. We will see how it works out. I need to figure out a hold down now. Might just go with the standard one on the MT faq.

self fusing silicone tape is good to 400 degrees F. it's really the best solution.

http://www.mcmaster.com/#self-fusing-tape/=e375z8

How much of a pain is it to apply. Looks difficult to work with? But looks effective.

will it work on that sort of wiring loom? I could see if working on something better like that weaved sleeve, but the split loom will collapse under the pressure needed to get the self fusing tape to really hold together.

it's super easy to work with. make it as tight or as loose as you want. it is self-fusing--you dont need to make it super tight if you dont want to.

oh okay. I might be getting confused with tension tape.

Great now I has a sad I used regular electrical tape :(

If it starts to fall apart the harness is so easy to remove and repair (I did my whole engine harness like the above) and I will fix it.

I think I used it on my cop harness actually. the coil connectors have a little barb-like fitting on them if I recall.. if you wrap the tape tight around that and loose around the loom, it'll stay put nicely.

mcmaster will have your ---- to you in a business day.

QUESTION...

If I have say a coolant temp sensor... and I have the coolant sensor wire running from the MS to it.. and the other is at a shared ground in the engine bay. Will that mess up the reading? Since it is normally grounded at the sensor ground off the MS?

So I have it like this..
MS-------CLT--------Chassis Ground

Stock is...
MS-------CLT--------Sensor GND off MS

For some reason I didn't really think about it until I was making the harness. What if I have the MS sensor GND wired to the chassis? ---- I'm dehydrated, hungry and tired. I'm sure I would normally know wtf to do.

If the MS sensor GND is shared with the chassis, you will be fine. But if its a floating ground, you won't be able to do that. I mean you could, but I don't think you will be happy with the result.

you should ground all sensors to the same spot off the block.

Aight.

I may be able to start the car this weekend. Wooooooooooo

For a neater "package", just wrap the ends of the wires in-line, heat shrink down the wire. Solder the two wires together and then heat shrink the joint together. Much cleaner harness.

Also, stagger the joints so that the entire bundle does not have a huge bulge.

Just a suggestion,

Jeff

That is going to melt on day one. I recently made a loom-wrap out of fire-sleeve and silicone tape. The silicone tape is easy like everyone said, just make sure the surfaces are clean. BatInc has good prices for the fire-sleeve and it's black.

Exactly why I didn't use it.