ms3 from scratch, no oem wiring

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ka240de
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ms3 from scratch, no oem wiring

Post by ka240de »

i know there are a few guys on here who wired their cars by themselves, as the title states i would like to dispose of all oem wiring and get my car running full standalone.
curious how complicated of a task this is,
full track car with no accessories, no heater, power steering, ms guages only, no air control, you get it.
information on the headlights and power windows etc doesnt matter.
just the coilpack, cas, cts, injectors, knock sensor and whatever else it will need to run.
i have 2 engine harnesses, and i already chopped all connectors off of one to wire from scratch (was i right in doing that?)

from what ive learnt the knock sensor is very simple, i also found diagrams while searching to wire the cas and ignition.

another quick question, is it advised to convert to map for n/a or should i hold up on that till i go f/i?
1991 sil-eighty se sold
1995 bmw 540i written off
1995 pathfinder se, sold
1995 Altima gxe, sold
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beercandrifter
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Re: ms3 from scratch, no oem wiring

Post by beercandrifter »

you are asking for 2 different things

ms3 runs your engine
-harness to control your accessories in your engine bay (i.e. fans, sensors, engine)

you would need a chassis harness to do the rest of your car (i.e. ezwiring, painless)

ms3 with the diyautotune prelabled harness on the ka is extremely easy to wire up (even easier to replace all the stock wiring utilizing the relay board they sell).

go map sensor right off the bat if you are using megasquirt, easy to tune and its much cheaper than a maf parts wise.

i have to say out of anything, wiring the fans was the worst part, I still dislike wiring fans to this day.

for the knock sensor, if you go ms3, buy the knock module up front and add it while you are putting together the ms3. get the expansion board as well (easy control of coil packs)

I really want to pull the stock chassis harness and put in one of the 12 or 18 circuit harness from ezwiring, primarily because getting access to switched vs 12v hot sources in the engine bay is a pain (plus the falling apart 20yr old harness part). only thing holding me back is not wanting to wire in the stock popup headlights.
91 240sx Hatch: HomeBrwd
25psi hx35/8.8:1/264^2 cams/95lb injectors/Megasquirt 2/ka24de build **RIP**
T56/4.8 LSx/LS9 Cam/60lb injectors/comp 918 springs/Megasquirt 3/all custom wiring
ka240de
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Re: ms3 from scratch, no oem wiring

Post by ka240de »

first of all i appreciate the help . these forums can be great!
i am fairly knowledgeable to everything i've done so far but wiring and tuning is a new playing field and i wont settle for less than Megasquirt definitely where its at. i will make sure to invest in the extras you mentioned and i did plan on getting the ms3x should have mentioned that.

also im running brick headlights :)
i would for sure only need a 12 circuit board from ez wiring i havent looked into it, but wouldnt really know where to start .
also i will go map right away. i asked because im going for the cleanest engine bay ever kinda thing.
1991 sil-eighty se sold
1995 bmw 540i written off
1995 pathfinder se, sold
1995 Altima gxe, sold
ka240de
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Location: humboldt, saskatchewan, canada

Re: ms3 from scratch, no oem wiring

Post by ka240de »

where is it tied in with the chassis harness? what if i tossed the chassis harness all together is there any way the car would ever run if i wired the fuel pump, scratch engine harness with said relay board, and wired up the ignition etc?

then worry about wiring door windows and lights separate ? cuz thats pretty much it for chassis electronics.
1991 sil-eighty se sold
1995 bmw 540i written off
1995 pathfinder se, sold
1995 Altima gxe, sold
ka240de
Knows Some Stuff About 240's!
Posts: 357
Joined: Wed Jul 31, 2013 8:34 pm
Location: humboldt, saskatchewan, canada

Re: ms3 from scratch, no oem wiring

Post by ka240de »

my shopping list is

assembled ms3x
assembled jimstim1.5
assembled relay board
6 circuit switch panel
antistatic wrist strap
jumper 10 pack
stim/ms power supply
10 foot harness
50mm trigger wheel
1991 sil-eighty se sold
1995 bmw 540i written off
1995 pathfinder se, sold
1995 Altima gxe, sold
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beercandrifter
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Re: ms3 from scratch, no oem wiring

Post by beercandrifter »

ms3+relay board will run
-engine
-fuel pump
-tach

stock lower harness still feeds speedo and runs the alternator/starter, reverse lights



ezwiring
-lights
-windows
-turn signals
-switch power source
-hot power source
(have a list of what circuits are included in the fuse block on their webpage based on what # of circuits you buy)



would suggest doing one at a time if i were you, its easy to get overwhelmed with wiring pretty quick. do the megasquirt first. you can get nissan connectors from a donor car to just make your ms3 harness plug and play with the stock harness (pretty much just the switched and hot power from the fuse block, one plug under the pass side fender)
91 240sx Hatch: HomeBrwd
25psi hx35/8.8:1/264^2 cams/95lb injectors/Megasquirt 2/ka24de build **RIP**
T56/4.8 LSx/LS9 Cam/60lb injectors/comp 918 springs/Megasquirt 3/all custom wiring
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Re: ms3 from scratch, no oem wiring

Post by Matt Cramer »

ka240de wrote:where is it tied in with the chassis harness?
The MS wiring just needs constant power, switched power, ground, and a fuel pump connection to function. You would also want to wire up the tachometer to it.
Matt at DIYAutoTune.com - Megasquirt ECUs, fuel injectors, wideband O2 sensor systems, and more
Nissan plug and play engine management now in stock!
ka240de
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Re: ms3 from scratch, no oem wiring

Post by ka240de »

okay sweet, so if its one thing at a time i could go ahead and take out all my chassis harness from under the dash ? i relocated the bay harness under the dash and its a pigsty! i could do that tonight. just want to confirm this before i do it because i spent 15$ on zipties and tape under there! i will do one thing at a time and i WILL get the ez wiring board if it allows me to delete my chassis harness.
any confirmation?

edit - looked into ez wiring standard-12 only $170!? im down for that.

*lower engine harness*
disregard reverse lights
starter to ez wiring / 6 rocker fuse panel
alternator not too sure but a search would probably solve that one.
1991 sil-eighty se sold
1995 bmw 540i written off
1995 pathfinder se, sold
1995 Altima gxe, sold
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beercandrifter
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Re: ms3 from scratch, no oem wiring

Post by beercandrifter »

some advice, dont cut the whole stock chassis harness under the dash. it does not end up well =)

Image
Image

you can use the harness going from the gauges to the brown connector passenger side by the ecu to make wiring a little easier.

btw you can find the ez harness on ebay for ~135 shipped if you look around, believe it is the mini blade fuse one.

do me a favor and take pics of the ez wire harness install for us all. I can contribute to the thread if you make it generic enough when i embark on that endeavor
91 240sx Hatch: HomeBrwd
25psi hx35/8.8:1/264^2 cams/95lb injectors/Megasquirt 2/ka24de build **RIP**
T56/4.8 LSx/LS9 Cam/60lb injectors/comp 918 springs/Megasquirt 3/all custom wiring
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Re: ms3 from scratch, no oem wiring

Post by Rick »

Damn... I remember wiring in my Link EMS on my S14 back in the day and it was a pain in the ass! Literally 2 months after I finally got everything working correctly AEM came out with a plug and play....

I do not envy you one bit. My wiring always started out looking awesome but by the end it was multicolored birds nest.
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ka240de
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Re: ms3 from scratch, no oem wiring

Post by ka240de »

yeah man thats exactly why i changed my plans again ! after more and more searching i decided i will get the plug and play version of megasquirt. my current setup is :

chopped oem fuse panel,
chopped oem relay panel,
oem ecu connector chopped
and some misc. relays,
all secured to a 2'x2' piece of plywood.

i have it setup with 8 fuse links and 8 relays, all else is depinned and the ecu connector has yet to be depinned of what im not using aswell. cuts alot of cost . all i need is a colour coded misc 23" wire set, alot of research, time, help, and a plug&play megasquirt. pics soon.
1991 sil-eighty se sold
1995 bmw 540i written off
1995 pathfinder se, sold
1995 Altima gxe, sold
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