D21 tach..

[JC87HB]

ok well my D21 (1987) has a gauge cluster but the cluster doesnt contain a Tach. I was just wondering if i would have the wiring to replace the cluster...And if so can someone link so pics or detailed instructions/information. Thanks guys

[Rev_D21]

I imagine the wiring is already in place. I would go to a junk yard to find a truck with a tach. Gut the cluster for the tach then transplant it into your cluster.

[JC87HB]

see heres the thing... my cluster the Odo went out like 1 month ago at 72k miles.... but my truck infact doesnt have the wiring...or maybe its hidden deep back, but when i looked it didnt have the same stuff as the 4x4 nissan pickup i lookd at like 10 min ago...and my problem is i dont know what the wiring looks like...its really unfortunate
Modified by JC87HB at 8:00 PM 9/4/2008

[Rev_D21]

FSM is all I can really say. The plug may be taped up and pulled out of the way where it can't easily be seen.

[rye1988]

just do what i did in my 93' hardbody, i put a aftermarket tach and mounted it on the dash, mine had a shift light, i like it alot, it was really quite easy to wire. heres what i did to wire it, first i looked on here and someone said there would be wiring for it behind the instrument cluster, i could not find that so i went the second best route, i ran the green wire for the rpm on the tach through the firewall where all the other wire go and ran it straight to the blue wire coming off the bottom of your power coil. i just spliced into it then electric taped it. the other three wires were simple enough, just wired the main power wire to my ignition so when i turn the truck to on the power goes to the tach, and the backround light i put onto my gauge switch so when i turn them on my tach backlight comes on too and then the ground i just ran to a ground under my dash that was not being used.

[rye1988]

so what i would do in your position is get a instrument cluster with a tach in it and plug in everything that can be plugged in then wire in the tach through different wires.

[mrecoolgar]

I have the same situation as you.I have a 90 with no tach.I have 2 or 3 gage clusters to try, plug and play.If not plug and play then the gage harness (which I also have) may need to be used.If that doesn't work then it's research time with the shop manual.I'm guessing that it is already wired, like the air conditioning.I do know the tach uses the computer.See my '1990 Redo Transformation' for updates.

[jdefelic]

In my '93 i used a tach out of a '92 240sx cluster. Bolted right in fine. Works great! You just have to change the needle from the white the 240 uses to the red the truck uses (speedo needle).

Locate a positive and negative inside the cluster to feed the tach with and run a wire to the coil and you can get the signal for it from there (i can find out what wire on the coil to use tomorrow if you intersted and get pics).

On second thought... maybe i located the signal wire inside the cluster... at any rate i will look tomorrow and take pictures

[jmd]

The tach wires are located in with the four plugs that plug into the cluster. the 4wd cluster is different only as far as indicator lights. the 4wd cluster will work in a 2wd and they are already prewired for tachs all you have to do is swap the clusters. That's easy, I just finished swapping a 97 dash and instument cluster into my 89, is the only reason I know about all the wiring aspects.

[mrecoolgar]

Thanks for the info guys.

[mrecoolgar]

I tried installing a gage cluster with tac today.My truck was wired for the tac and the clock.The small 2 wire connector is for the clock.The other small 4 wire connector is for the tac.However the tac never worked.Everything else worked, signals, hazzards, hi-beams, brake, fuel ...All but the tac.Either the tac is bad or I'm missing a step.The top gage unit is my original without tach.The bottom gage unit has the tac.

[jmd]

check and see, i think there may be a fuse you might need to install for the tach to work. i would check for you but i'm not at my shop to see. I will check on it tomorrow and let you know if you don't figure it out by then.

[mrecoolgar]

Gotcha, I'll check the schematics.Thanks for the tip.

[Lakehimself]

Gotcha, I'll check the schematics.Thanks for the tip.

I put a tach in my 91 d21 and I looked everywhere and I couldnt find where to do it, so I took it to a friend who found the wire I needed to hook up the tach

[Rev_D21]

I put a tach in my 91 d21 and I looked everywhere and I couldnt find where to do it, so I took it to a friend who found the wire I needed to hook up the tach

Where was it? What color/stripes? Just so other people who read this thread will know. Spill the beans!

[240sxFTW]

spill the beans! what wire do i use for an aftermarket tach??

[zack.]

I tried installing a gage cluster with tac today.My truck was wired for the tac and the clock.The small 2 wire connector is for the clock.The other small 4 wire connector is for the tac.However the tac never worked.Everything else worked, signals, hazzards, hi-beams, brake, fuel ...All but the tac.Either the tac is bad or I'm missing a step.\

check and see, i think there may be a fuse you might need to install for the tach to work.

not sure for the d21, but when i had my 84 720 this was turned out to be the case. i even took a tach back to the junkyard to exchange it before i realized the tach wasn't the problem.

[mrecoolgar]

I'll need to address this now since the dash is out.Hopefully I'll figure it out in the next several weeks.

[JLaines]

Greetings from wintery Finland!

I readed this topic lately, because I had a similar problem with my King Cab. Thou it´s a euro spec diesel version, it all so has the tachometer plug ready in the combination meter wiring harness. And suprisingly my cars tacho didn´t work either.

So here is a short story what I did (may help you guys all so, if we forget the diesel part )

The TD25 diesel engine has a separate tachosensor near timing gear. The trail of this thingy I got from a local Nissan-dealer. Allthought I checked spare part number and location from HERE. Nissan4u site is a great place for people, who are searching part numbers for their cars. Next step was this SITE. It contains wiring diagrams for WD21 Nissan Terrano which should be similar to North American market Pathfinder and D21 pick up ( it did not help me, because diesel wasn´t in the book). I hope these little things are helpfull for you guys beyond atlantic ocean

[dickhamlet]

I've just swapped an instrument cluster into a 1987 Nissan D21 extended
cab pickup. The new cluster from a junkyard has a tach and a clock; don't
know its year or model, but it's an exact fit for the old one that had
no tach. All the cable plugs were there, they fit and everything except
the tach worked immediately. The 4-prong plug into the tach (three live prongs)
has +12V, ground, and signal. On my truck the signal wire is white with
red splotchs, but colors may vary by year. I could not trace where this
wire goes and it seemed to be dead, so I started to search for a signal.

Several websites suggested various tach signal sources, but the only one
that would drive a 12V test light was off the transistor connected to
one of the coils. (Forgot to say that my truck has a Z24i engine, with
two coils and 8 plugs for four cylinders.) One site says this worked,
but I was a bit leery of it--there evidently was a tach connection
somewhere else. A local shop got me a wiring diagram for a 1995 truck,
which indicated that the tach is driven off the ECU computer. It also
showed several places where there were variations between the tach- and
non-tach wiring. Apparently the reason why the tach wasn't working is
that I had these variations, but I could not locate them in the actual
witing.

The ECU is located under the passenger seat. I tested lots of pins
on the ECU, but nothing detectable with a test light or a multimeter.
The wiring diagram showed tach signal on pin #3 of the left connector
(looking in from the passenger door). The pin numbers on the connectors
are stamped into the plastic, sometimes only "1" at one end if there isn't
space to stamp. No detectable signal on pin #3, (wire white with red splotches,
but not connected to the same-color tach wire) except that putting the
test light there made the engine stutter slightly. I guessed that one of
those alternate connections in the non-tach harness was breaking the path,
so I ran a wire direct from ECU pin 3 to the tach-signal connector on
the cluster, which worked perfectly. The circuit is evidently very high
impedance, low voltage, which is why it doesn't show on crude testers.
I ran it through a 100Kohm resistor at first, but then the tach didn't
work, so I made a direct connection. (The wiring diagram doesn't show
a resistor, but the Haynes manual did.)

Since the wiring diagram I had is for 1995, this tach signal should
probably work for a wide range of years. But it would take an
oscilliscope to see just what the signal is. It might not drive
after-market tachs because of the high impedance.

[mrecoolgar]

I thought I posted my end findings here but I guess not.
Thanks for the above help.
The problem was a bad tach, not the install.
I ended up putting that gage cluster from my 1990 2WD in a 1990 4x4 hardbody and the tach didn't work there either.
However, the tach from the 1990 4x4 gage cluster did work in my 2WD.

So to sum up... the tach is plug and play.
The wiring is there and it will work.
If not, the tach is bad.

[anthony1988]

The tach wires are located in with the four plugs that plug into the cluster. the 4wd cluster is different only as far as indicator lights. the 4wd cluster will work in a 2wd and they are already prewired for tachs all you have to do is swap the clusters. That's easy, I just finished swapping a 97 dash and instument cluster into my 89, is the only reason I know about all the wiring aspects.

SO your saying that all d21s are prewired for tachs?because today i took my 1988 Nissan D21 gauge cluster apart and did not find the 4 pronged wire that wires the Tachometer.. or is it hidden some where? if so where is it hidden at??

[osegundo]

I installed a gauge cluster from a pathy into my 89 d21 4x4 and the tach doesn't work!! Ive also read about it too that pathy tachs won't work on trucks!! Oh yeah my wiring was taped up and tucked away ... but it should be there!!!

[Rev_D21]

Pathy tachs do work in the updated dash trucks but you must use a 6 cylinder tach in a 6 cyl truck or else it will not read correctly.

[osegundo]

What about the square dash? Is it really true that the pathy tach won't work in a truck? Or is it a myth? But to tell you the truth I'm on sure if the pathy was a 4 or 6!! I've never even seen a pathy with a 4 cylinder!!

[Rev_D21]

Some Pathys were 4cyl. Some were 2wd too. I can't speak for the square dash, only the curvy. I have a Pathy cluster base and tach gauge face in my 4cylinder truck. I had to swap tach motors to make it work and if you look at my gauges you will notice my redline is different, that's because it's a 6cyl redline from a Pathy. I did the swap to make my clock work.

[anthony1988]

so basically the tachometer wiring is hidden and tucked away is that why we cant find it easily??

[osegundo]

so basically the tachometer wiring is hidden and tucked away is that why we cant find it easily??

Yeah the wiring should be there.... on mine the tach plug and the clock plug were taped together and tucked away!! After you remove your gauge cluster you should look way back behind from where all the gauge wires come from!!

[anthony1988]

okay and what year is your? mines and 1988 model the real basic model with no options to do you figure that will have all the wires even though its really basic? like does your have power steering? Or A/C? plus did your tach work after you converted it?

[osegundo]

Mines "89 and and it only has power steering!! No a/c, power windows, or power mirrors!! The gauge cluster works except for the tach on mine!! Also make sure its not taped to your gauge cluster wiring because I guess it could be wrapped in tape on your gauge harness!!