Tach stepper motor replacement info needed.

[Yeti_Owner]

Here's my thought:

You already tried it without changing the board, and the tach was high, which means nothing in the stream before the cluster denotes V6/V8 as far as signal interpolation is concerned. It's *got* to be on that board.

Provided your clusters are otherwise the same (same #/type/location of gauges and indicator lights), a board swap should do it. The motors and gauges are only going to read what the board feeds 'em.

I think it'll work, and be accurate.

As per all my earlier stuff, I was operating under the assumption you *only* had the V8 cluster, lol. That's why I was nit-noiding over component numbers and functions - IE "What do we have to buy at radio-shack and solder onto this sucker to make it work?"

 

[sewlow]

Actually the V8 tach wasn't high when used behind the 6. More like a Mexican jumping bean! Extremely distracting!
I agree! Common sense would indicate that the signal would be read within the board. But then, GM engineers & common sense aren't words always used in the same sentence!
As far as I can see, the clusters are the same. Gauges, indicator lights etc. They're both from '98's.
And yea, I have 90% of the parts I remove or replace when I mod something. It's NOT hoarding! Really! They're for 'just-in-case' a mod doesn't work! Which has been known to happen on occasion! Lol!

 

[great white]

It all depends what the tach signal is coming from. If it's coming from the crank position sensor, it's probably going to the PCM first and then the cluster.... just spit balling here.

By all means swap the boards, you've got nothing to lose.

 

[Yeti_Owner]

Here's the breakdown of the IC components (ignoring resistors and diodes for the moment (just for laughs) that I'm seeing:

V6:
Board 16183928E
8674 -cs9731s (2)
16121016C-CTS9719 (1)
AMI Chip C19946 (1)
06548- 9731n - 5197086(1)
5333-2989 cs732b(1)
yellow .068uf capacitor

Esky V8:
Board 16183928J
8674 - cs9952s(2)
16121016C-CTS0004 (1)
AMI Chip (Illeg. but doesn't matter, looks like it runs either a gear position indicator or some form of indicator lamp set by the LED's tracing to it)
06548-01955011-519rn005C (1)
5333-2989 -cs0058(B?) (1)
yellow .068uf capacitor

97 Yuk V8 100mph Cluster:
Board 16183928E
8674 - CS9643S (2)
16151016C - CTS9645
AMI C19946
5333-2989-CS640B (1)
06548-9638n-?5?19612?0?
yellow .068UF cap


Question, because it's been a while since my fundamental electronic engineering classes. WTF are those things that are brown on both V8 clusters and blue on the V6 ones ..resistors, diodes, or inductors? If they are inductors, the lamda would change the dwell on the signal to something, right? Or are they teeny tiny caps? If so, why are they a different color...hmm

 

[Yeti_Owner]

Ah, they are diodes.

 

[great white]

So, dug up some wring diagrams and was looking at a 96 5.7 vortec.

The speedo signal comes from the pcm and it appears the tach signal comes from the ign coil like older trucks.

I say swap the board and the tach will work.

The speedo will be a question until you get it in snd running. Im thinking its going to be messed up because of the range differences. You may be able to compensate with your "interrupter" box though.

Give it a try...

 

[Yeti_Owner]

So, dug up some wring diagrams and was looking at a 96 5.7 vortec.

The speedo signal comes from the pcm and it appears the tach signal comes from the ign coil like older trucks.

I say swap the board and the tach will work.

The speedo will be a question until you get it in snd running. Im thinking its going to be messed up because of the range differences. You may be able to compensate with your "interrupter" box though.

Give it a try...

Agreed

 

[Yeti_Owner]

Can't wait to see if it works!

 

[Yeti_Owner]

Results?

 

[sewlow]

Sorry guys, no results yet. Gotta project that has to go out the door, PDQ. Didn't get to work on this yesterday. Should have something for you by the weekend!