# Tachometer Install



## Cuban_B_93_XE (Apr 24, 2003)

Anyone know how to wire up a Matrix Tachometer (Pep Boys Type)? Im really lost on this one!


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## Sentra_Industies (Oct 31, 2002)

Ground Wire - to the chasis
Power wire - tap into radio power wire
Signal wire - tap into a blue wire with white dots on it (i think) that is on the computer harness


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## toolapcfan (Jul 10, 2002)

Seems like I've answered this one a million times, one more time won't hurt.  Like Sentra_Industies mentioned, run the positive wire to an ignition on, positive source, that way it only works when the car is on. Ground the ground wire (obviously), find the blue wire with a black stripe coming out of your ECU and connect your tach sensing wire to this (it can be found abandoned in a harness behind the hvac controls). For your backlight on the tach, pull your dimmer switch out of the dash and connect the backlight's positive wire to the dimmer's red wire with a blue stripe, and the backlight's ground wire to the dimmer's red wire with a yellow stripe. Your tach will only come one when the car is on, it will light up when you have your lights on, and it will dim with the dimmer control along with your other dash lights. If you have any questions drop me a PM or E-mail.


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## insanestvtop (Dec 3, 2002)

on my car it was a blue wire with one silver dot about in the middle more on the left side if you are looking at the ecu. At least that was for my 94 sentra le


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## toolapcfan (Jul 10, 2002)

It still should have had a stripe on it though.


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## insanestvtop (Dec 3, 2002)

yea, sorry blue wire white stripe and one silver dot


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## toolapcfan (Jul 10, 2002)

The blue wire with a white stripe is the one from the coil to the ecu, this will work for an aftermarket tach but could fry and OEM one. The blue with a black stripe is the one installed that the OEM tach would have connected to. Bear in mind there are more than one blue/white and blue/black wire coming out of the ECU, so you need to use a pinout to find the right one. Like this:










The blue/black tach wire is pin #2. 

If you need more info on your gauge cluster in general you can refer to the write-up I did for NPM awhile back:

http://www.nissanperformancemag.com/february03/b13cluster/


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## SentraE (Jun 28, 2003)

Is all this info good for cars that did not come with an OE tach. because i plan on hooking up a tach in a week or 2 and my car doesn't even have an OE tach.


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## toolapcfan (Jul 10, 2002)

Yes, it will work for either.


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## insanestvtop (Dec 3, 2002)

one thing that work well for me, but not the best way to do it, is i hooked up every other wire on the tach and took a metal probe and probed each possible wire hook up on my ecu and found out which one worked, but i am kinda confused everyone says its the blue with black, but mine was a blue with white, possible difference between one with oem tach and not?


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## toolapcfan (Jul 10, 2002)

"i am kinda confused everyone says its the blue with black, but mine was a blue with white, possible difference between one with oem tach and not?"

The blue wire with a white stripe is the one from the coil to the ecu, this will work for an aftermarket tach but could fry an OEM one. The blue with a black stripe is the one installed that the OEM tach would have connected to. I connected my aftermarket tach in my '93 XE to the blue with a white stripe wire as well, and yes it works, BUT I try not to get into the habit of telling people to use that wire because if they opt to put an OEM cluster in, that wire could fry the tach. So I just tell people to use the Blue with a black stripe wire since 1) it is the one used to operate the OEM tach. 2) It will operate an aftermarket tach. 3) It's easier to locate and tap into the blue/black wire than it is to do so with the blue/white. All B13's have the blue/black wire going from the ecu to that connector I mentioned. It just doesn't make it into any of the cluster harnesses in cars without tachs, since it isn't used. 

It's funny because I was at the junkyard today in a '94 Sentra and I dug around and found the connector where you can tap into the Blue wire with a black stripe (and it also has silver dots on it). It's a white connector with 6 terminals in it with space for 8 if i recall correctly and it's located just behind the HVAC controls on the drivers side.


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