shift_6x

i am looking for my tachometer wire, i have been told that it is a yellow/red wire that is located on AN engine coil. i am not sure how many coils 350's have. i am confused, if anybody can help me find this wire i would really appreciate it.

KPierson

iTrader: (1)

I haven't found my tach wire yet, but maybe I can help.

DEI lists the tach on an 04 350Z as:
Tachometer NOT black or white/blue (ac signal) at any ignition coil.

The ignition coils are mounted basically right on the spark plugs, meaning there are six of them. Take the engine cover off and locate the spark plugs. There should be 2 or 3 wires coming off of the coil that is attached to the plug. From DEIs description it sounds like there will be three wires in the harness and that black and white/blue will be in all 6 harnesses with the signal wire being a different color. It doesn't matter what spark plug you use, they will all work. If you get a chance take a picture of the what you find and post it for all to see!

Kevin Pierson
www.kptechnologies.net

NY 350Z

iTrader: (9)

ive been wondering this also...i have a pivot shift system here waiting to be installed...the nissan dealership told me that hookinh it up to any coil will be fine.

but i dont wanna go into splicing wires if i dont know which one it is.

NY 350Z

iTrader: (9)

also...if its possible to somehow just connect the shift light to the stock rev light thatd be alot easier...know anything about that?

KPierson

iTrader: (1)

You will probably get better, more accurate results using a coil for your signal. To test the suspect wire attach the black wire of your DMM to a ground on the vehicle and attach the red wire to the wire you want to test. Set your meter to read AC voltages, 0-2 volts if it isn't autoranging. With the car started and idling the the wire should read a very low voltage, close to 0 volts. Next, have someone rev the car up a little. The voltage should rise with the RPMs of the engine. If you are working by yourself it is usually possible to place the meter on the windshield and then hook your wires up, that way you can read it from inside why you are pressing the pedal.

The reason you need to set your meter to AC is because this is a squarewave pulse and not a steady DC signal.

Also, against my better judgement, I will tell you that I have seen tach wires (on remote start systems) hooked up to a variety of differnt (read: wrong) places in cars. Fortunately, whatever you are hooking to this wire should be electronically setup to not draw any current or alter the signal it is attached to at all, meaning that you most likely will not damage the car by hooking a tach wire up something that isn't a tach source. Sorry for the book, if you have any questions let me know.

Kevin

NY 350Z

iTrader: (9)

DMM, AC (air conditioning?)

damn i didnt think id need a voltage meter and all that. i jsut wanna plug and play!

KPierson

iTrader: (1)

You should ALWAYS verify EVERY wire you ever tap into on a vehicle. People make mistakes when giving wire locations and colors. Installers have momentary lapses of inteligence. One of my managers back in the day - Patrick - thought he knew the ignion colors of Ford trucks. When he was done he had the starter wire and ignition wire backwards. Talk about terrible noises coming from a shop....

Every GM vehicle since 75 have used the same color igniton wires, yet I still test every sigle one before I tap into it.

Kevin

shift_6x

thanks for the info. my digital camera broke a few weeks ago so i have not the ability YET to show pictures, but i will still try to post the pictures if i can get a camera as i know that pictures speak a thousand words. thanks again.

shift_6x

looking at 2 different wire connection guides, it took trial and error in trying to find the door ajar indicating wires. both company's i got the diagrams from had to revise their wire color guide because it was wrong. I ended up having to use a switching diode for 2 door ajar wires for the alarm input wire when they weren't even the right wires. in my experience especially with a brand new model, you can't trust what is said all the time, speaking from experience, it would be very wise to check the wires before connecting them to your alarm. if anyone needs to know where the wires are i can inform you from my experience, but this car is not easy to install an alarm on, led alone a remote start. very few places to hide modules, valet switches, ect. make sure you have enough time to do it also. takes at LEAST a couple days for an unexperienced person.

KPierson

iTrader: (1)

I stopped into the local speed shop today and they had a 350z they are supercharging. I poked my head in and found the Tach wire (for me and the guy working on the car )

Once you take the engine cover off you can see where the spark plugs screw into the block. On top of the plugs, like I had guessed, is an electronic module with three wires coming off of it. The wires are in a black sheething. There are 3 of these harnesses per engine side. Tap into any of them - not the black or white/blue wire - and you should be set. The coil I saw had a green wire as the third. I would recomend using one of the coils from the plug that is closest to the front of the car, as they are easiest to get to and work with. I also snapped a pic with my phone, but I haven't uploaded it yet, if you want to see it let me know!

Kevin

shift_6x

kevin, thanks for the info man.

i have my engine cover off right now, i know what you mean here, i saw that there are many colors per coil. i have a fluke 87 dmm and i connected the wire (green/black) to my meter and i reved my engine, but i was hesitant to connect my module wire to this "tach wire". i am used to high ac output voltage readings and this raised only 0.8 volts. it started at 0.1 and at around 5000 rpm's it only read 0.9, it raised smoothly as the rpm's jumped up, but i was thinking that it would raise a little more that, i am going to go ahead and connect this anyway because now that i see you have found this for me and you initially said to set the dmm to 0-2 volts, this must be the wire. thank you again for your help. if you could post that pic that would probably give me more reassurance that i didn't tap into something i shouldn't have, but i am pretty sure i got it. thanks again.

KPierson

iTrader: (1)

Sounds like you got your wire. Tach wires rarely raise up above 1 volt. Basically depends on the engine though. Good eye on that 0 - 2 volt range. I'm not even sure if such a range exists as I have never owned a meter that wasn't auto-ranging.

Good choice on the Fluke - I have a Fluke 87 and a Fluke 189. Love em!

Kevin

shift_6x

thanks again kevin. i am fiiiinally finished with this remote start now with your help. all i have to do now is just program it so i can use it. i am happy with my fluke 87, i have had it for about 4 years now and it has definately lent a helping hand in many projects.

shift_6x

how do you get access to DEI? i have been trying to get their wire list. i just need to see what they list for trunk release. i have it listed as a pink (-) wire in the brown plug at BCM. but my meter reads it being (+) in polarity.

KPierson

iTrader: (1)

I used to work for an authorized dealer....

DEI shows it being a (-) pink wire also. It is a BCM input, so I would imagine it should read 5vdc when the button isn't being pushed, and then should go to ground with the button is pushed. (Like the VDC button). I'm not sure of any BCM inputs that are 12 volt. I will check my service manual later today, I can't now cuz I'm already 30 minutes late for work

Kevin

JohnBoy

You can also get the tach wire from any of the 6 coils at the ECM. That might be a little easier than running a wire into the engine compartment. I connected to the ecm for the remote start on my G35 6MT and the service manual for the Z shows the same thing. Double check your wire colors though as mine differed from the service manual.

As for the trunk switch, I also see it as the pink wire in the brown connector at the BCM. It is pin 76 which is the bottom left pin as you look from the harness side with the clip on top. When not being pressed, it should rest at about 5 volts. Maybe that's what you're seeing when you probe it?

~JohnBoy

shift_6x

exactly JohnBoy, i am reading 5 volts, but when i press my factory trunk release button it doesn't seem like it is grounding. i know that it will have a momentary ground being that it is a switch, but the meter reads it at 4.91vdc, then when i hit the trunk release button, it briefly goes to 4.94. so i am seeing SOMETHING. but no ground, thanks for both inputs on this, you have been a real big help. i just wanted to see if i should be reading the 5vdc instead of -5vdc, since i am at least seeing some action when i hit the trunk release, i will go ahead and connect the wires, im just worried because it warns me in the manual not to connect relay to the wrong wire for it might cause the switch to fail. that would really suck, i feel more confident now thanks to both of you.

ps. kevin i hope you didn't get into any trouble being late for work!
i appreciate your time and research.

KPierson

iTrader: (1)

It is actually pretty nice working in a different time zone then you live in. It gives you the ability to be 30 minutes late and now one really cares. I guess they kinda figure that if I'm driving 140 miles to come visit them for the day that I can get there when I want!

I got a few suggestions -

instead of pushing, hold the button down for a few seconds. If the wire goes to ground then that is your wire. If not -

Hit the range button a few times on your multimeter so that the display reads 0.00
The meter will respond MUCH quicker to changes with auto ranging shut off. If it is the typical Nissan pulse it will only be about .3 seconds long - just barely long enough for my Fluke 189 to register the change.

Last resort - Get a fuse holder and a 1 amp fuse. Tie one end of the fuse to ground and quickly touch the other end to the suspect wire. If the trunk pops that is your wire. If the fuse blows or nothing happens you have picked the wrong wire. The reason you are reading 5volts on the wire is because there is an internal pull up resistor in the BCM that holds the line high (essential for digital interpretation). Applying a groudn to it should not hurt anything - especially if it is fused and a very brief pulse.

Let us know what you find!

Kevin
www.kptechnologies.net

JohnBoy

Also, check your trunk opener cancel switch (it's in the glovebox on the G so I'd guess the it'd be in the same place on the Z). If that's turned on (cancelling the trunk opener) then you won't see the ground at the BCM when you hit the opener switch. Of course, the opener switch itself won't open the trunk either if the cancel switch is turned on.

KPierson

iTrader: (1)

Good thinking captain obvious! I have a terrible problem of trying to make things a lot harder then they need to be, and often look past possible solutions that are right there! I think we have now covered everyting possible, besides going right to the switch and using those wires.

I checked the service manual and found that the trunk release switch is a momentary switch. As long as you hold the button down the wire should read ground.

From everything we've posted so far I am going to recomend that you check that cut-off switch like John suggested, cuz that is what it sounds like it is. Either that, or you got the wrong wire!

When you push the button is the trunk popping?

Keep us updated,

Kevin