Just got my new tach board in the mail today.
Here’s what you get when you order a new tach board for the 86-88 V6’s. (see pic below)
This is being installed in my 85 GT, which was upgraded to the 120 Speedo and aux. gauge pkg. years ago. The reason for the tach swap is my current one is showing +500 rpm than is actual. (as verified by my Scantool program) Also, I know that some modify/adjust/recalibrate the old one but I felt it was wiser to simply go with a new one as the components are “fresher” than the original ones, which are fast approaching 40+ years now.
I’ll be getting started in a few days and will post pics along the way.
And, to verify that the new one is calibrated correctly, I’m going to run my scan tool program before I put the instrument cluster back in its place. Kit

[This message has been edited by Kitskaboodle (edited 05-19-2025).]

I rotated the image for you Kit...



------------------
Original Owner of a Silver '88 GT
Under 'Production Refurbishment' @ 136k Miles

[This message has been edited by Vintage-Nut (edited 05-19-2025).]

------------------
"Turbo Slug" - '87 Fiero GT. 3800 turbo. - The fastest Fiero in France! @turboslugfiero
https://youtu.be/hUzOAeyWLfM

Ok, I made a lot of progress today. Here is what I have done:

1) Removed cluster pod and put it on my workbench.
2) Removed instrument cluster from pod assembly.
3) Removed clear plastic bezel and black/orange cover plate from cluster.
4) Removed speedo assy. from cluster (white) housing. (pulls up & out / no screws to undo)
5) Removed screws that hold in tach assy., carefully placed my fingers under the tach and lifted tach assy. up & out of the housing.
6) Removed old tach board from the back of the tach gauge round can metal housing. (3 standoff screws)
7) Installed new tach board onto tach gauge round metal can housing.
8) Installed tach board assy. back into cluster white housing.
9) Re-installed speedo assy. back into cluster white housing.

Important suggestions & notations:
It pays to be thorough & detailed when taking apart 40 year old stuff. Here’s why….
Notice in the pic above that I have some green corrosion on the copper traces of the connector that is on the left (drivers) side of the cluster. (not sure if you can really see the green corrosion but it’s there on the first and last pins) I will clean this up but my point is to examine stuff when you take electrical connectors apart.
Next post will address a change I made to the Speedo pc board.
P.S. See that plastic doo-dad at the lower left of the pic? It’s kind of “T” shaped, has a single plastic post that snaps into a hole and is meant to hold a loom of wire in place? What do you call this type of fastener? My Reatta uses these also and I could never find them on Amazon. I know what they’re for but I don’t know what you call them. What specifically are they?

[This message has been edited by Kitskaboodle (edited 05-20-2025).]

Post# 2:
While I was in the cluster housing, I decided to check over & examine the Speedo assy. Sure enough, the one and only electrolytic cap on the Speedo pc board had some corrosion on the negative end of the cap. For this reason plus the fact that this lytic is 40 yrs old., I decided to replace it. For those who don’t know, this cap is 150uf / 25 volt. I
replaced it with a 220uf / 63 volt cap, which should be fine. Here’s a pic of the old cap before I replaced it. (not sure you can see the white corrosion in the pic) Good news is you can replace it without removing the pc board from the Speedo assy. Kit

[This message has been edited by Kitskaboodle (edited 05-20-2025).]

Post#3:
On a different note (and in a different thread) we were all talking about the Fiero shift light and which clusters had the shift light capability and which ones didn’t. Well, I don’t remember exactly what car I took this cluster from but my suspicions are that all Fiero clusters had this capability. (I could be wrong though)
Here’s a pic of the shift light lens from my cluster that’s
from an 86-88 V6 car.
Kit

[This message has been edited by Kitskaboodle (edited 05-20-2025).]

[This message has been edited by Kitskaboodle (edited 05-20-2025).]