Black88Z

My stock tach is garbage, doesnt work at all. I have an aftermarket tach laying around so i decided to use it.

I mounted it with no problem, but im wondering if anyone has any tips/suggestions or if they can answer a few questions.

Can I hook up the power wire to the fuse in the fuse box labeled "gauges"?

Can I pull the cluster out and splice or cut the wire to the tach there, then hook up the new tachs' wire there? Rather than running it all the way around and to the coil.

Thanks

Apeiron

That will work fine.

Black88Z

Thanks. Is it the same white wire like the wire on the gray connector on the coil? (The one that runs to stock tach)

vetteoz

iTrader: (13)

Yes

Black88Z

Alright, just wanted to be sure before i go out and start pulling things apart. Thanks again!

Black88Z

Alright, it really shouldnt be this difficult. Ive hooked everything up and the backlight works, but the tach needle itself doesnt. I read this fourom and did as it says.

I bought it from a friend that says it works, but i never saw it in action.

I checked the ground and its great. The light wouldnt work if that was the problem anyways.

The power (red) wire i put a male connector on the end and plugged it into the IGN fuse spot (was nothing there on my car anyways). This is how i was told to do it in the article i posted below. I saw a small spark the first time, but now i cant seem to see it if i plug it back in there (probably just unable to see it) i checked the spot with a meter and its got power to it.

I plugged the green wire on the tach (tach wire) into another wire then hooked that up to the white coil wire.directly into the coil wire itself (as described in the post) and still isnt working.

Can anybody help please?? This is very frustrating and irritating, its a fairly simple thing to do yet the stupid thing doesnt want to work.

Heres picture of where i connected the jumper wire to the coil wire. I only did it like that for testing purposes, i dont actually leave it that way of course.



THIS IS WHAT THE FOUROM SAID:


HOWTO INSTALL AN AFTERMARKET TACH IN A 1987 thirdGen in the hopes it will help some of you.

1) Disconnect battery
2) Remove Vanity plate over distributor
3) Find the external coil, it should have 2 connectors on it.
4) Remove BOTH connectors, don't worry they are keyed and only go on 1 way. (you have to pull a retainer to remove the clip)
5) Find the GRAY connector with the pink wire and the white wire
6) Clip the white wire. somewhere in the middle.
7) Reconnect the coil connectors BOTH OF THEM.
8) Reconnect the battery and start the car. You will notice that the old crusty stock tach NO LONGER WORKS BUT THE CAR RUNS.
COOL, eh?
9) If you have removed the airconditioning vents in the center dash, install the tach (mine is an Autometer Monster Tach with shift light). Run the wires down thru the dash to the firewall, find a hole up around the master brake cylinder.
10) Hook the RED WIRE to the IGN plug in the fuse panel, it will need a male connector on the end to plug it in.
11) Hook the Black wire to the ground (i used the bolt at the far left under side of the dash with a nice extra washer)
12) Run the green wire thru the firewall and up to the COIL. Be sure and protect it well (i used some 1/4 inch rubber tube to ensure it didn't rub on the firewall.)
13) Strip and attach this green wire to the STUB OF THE WHITE WIRE YOU CLIPPED IN STEP #6 ABOVE)
14) IF you have headlight / dash lights you may want to hook up the backlight by using the WHITE WIRE FROM THE TACH. (it may be powered by the RED WIRE as an option).

TESTING:
Get in the car and turn the igniton part of the way, DO NOT START THE CAR JUST YET.....

SEE IF THE TACH RESETS, if it does, you are OK. (RESET MEANS GOING TO ZERO). IF it doesn't, you want to STOP and double check steps 1-14 to be sure you did them right. If it reset,
Then you are free to start it up and take a spin around the block.

ENJOY, A TACH THAT ACTUALLY WORKS, instead of a stock one that is 500-1000 RPM OFF. Mine was WILDLY INACCURATE.


My tach is already at 0 (the new one), even when it was completely disconnected. IDK if that affects anything.

Thanks for the help

vetteoz

iTrader: (13)

What is WRONG with your picture ?????????????????
You have NO CONNECTION TO THE COIL tacho wire at all

Hint.
The white wire you are connected to goes to the old tacho in the dash
the coil wire ( for tacho ) is on the gray plug

Install instructions you quoted say
13) Strip and attach this green wire to the STUB OF THE WHITE WIRE not the longer wire to the harness

Black88Z

Lol!! Oh man, do I feel stupid. Im glad it was something small though. I double checked so many things, but when i still didnt figure out the problem it just started frustrating me and you lose the ability to think clearly, you know? Glad that it was so simple, just needed a new set of eyes to notice my eff-up. Thanks again Oz

snipzors

ok guys i know this is an old thread but i have to jump in here , 87 tpi setup, followed this exact post save for the error made and when i go to turn ignition the tach was already at zero so didnt move or reset, so i fire it up..... except now the car wont even start it just keeps turning over.... what is going on here, i have no idea what i did now

Hunter0075

Where is a good place to install a aftermarket TACH? And looks good in the car.

snipzors

got mine all working, because if a relocated ignition coil that was done previous to me owning the car, i had to get tach signal elsewhere but all good now

snipzors

@hunter0075 i did a small 2" tach and mounted it under the dash pad just to the left of the headlight on pull switch

Hunter0075

thanks

Black88Z

It depends on what you want. Ive seen tachs installed in/on the A pillar, directly on the dash pad, in front of the original tach, even mounted on the roof! I mounted mine on the dashpad, drilled a small hole behind it to run the wires thru and then ran the wires thru the dash to where they need ti go. Really, very easy.

It gets the job done, and when your going fast its best because you dont have to look down from the road for long to see where the rpms are at. I personally like how it looks too, i think it looks real race-ready lol

Annihilate

iTrader: (1)

Again, sorry to bump an old thread. But I am curious as to how I would hook up the tach illumination to the headlight switch. So I can turn it on and off.

Edit: Solved. I am going to hook it up to the Dark Green Dimmer wire. Thanks anyways guys!

Mr.ChevyStroker

So I followed these rules on my 91 rs 305 and the tach isnt working. And idea whats wrong?

IrocChuck

So what is the black connector for? Thanks

Wickydooda

iTrader: (1)

Found this on another thread.