Difference in tach signal

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

laidbackbigun

I'm Awesome
Joined
Nov 30, 2015
Messages
561
Reaction score
278
Location
Oxford, PA
Okay while troubleshooting my high voltage problem i have noticed that all 3 clusters i have gotten the tach is wild. My tac for the 95 reads just fine but when i plug in the cluster from the vortec trucks the tach runs way high and wild. Is the tach signsl different? How do i rectify this?
 

RawbDidIt

I'm Awesome
Joined
Mar 29, 2017
Messages
1,034
Reaction score
690
Location
Dallas, TX
I know the 95 is weird, it wouldn't surprise me a bit if the tach signal is off too. I'll see if I can find confirmation.

Sent from my SM-G965U using Tapatalk
 

RawbDidIt

I'm Awesome
Joined
Mar 29, 2017
Messages
1,034
Reaction score
690
Location
Dallas, TX
The only thing I've found is that the Dorman replacement for dashes extends from 96-99. Can't find a dash replacement for 95 at a reputable site, but I'd bet it is a different part number than the one for vortec years. You may need to find another instrument panel from 95

Sent from my SM-G965U using Tapatalk
 

east302

I'm Awesome
Joined
Oct 4, 2013
Messages
3,407
Reaction score
3,121
Location
Jackson, MS
On the vortec, the tach signal comes from the ignition coil. Not sure if that’s different for the TBI. The clusters are specific for V6, 8 and diesel, so that would need to match.

Someone on here said they swapped a (Escalade?) cluster into a 95 and had no issues.

Also the ranges are different...

1995:
You must be registered for see images attach


1996:
You must be registered for see images attach


1997+
You must be registered for see images attach



Sent from my iPhone using Tapatalk
 

laidbackbigun

I'm Awesome
Joined
Nov 30, 2015
Messages
561
Reaction score
278
Location
Oxford, PA
Yeah i noticed the ranges were different as well. I did notice that on the backnof the 95 cluster there is a resister soldered in to one track of printed circuit. Im just wondering if i put one of those hei filters in line with the tach signal wire would it clean it up kinda like installing a aftermarket tach on my 92 was.
 

laidbackbigun

I'm Awesome
Joined
Nov 30, 2015
Messages
561
Reaction score
278
Location
Oxford, PA
Anyone know how to just diable the tach. Id rather not have it work at all than be all bouncy and a distraction
 

RawbDidIt

I'm Awesome
Joined
Mar 29, 2017
Messages
1,034
Reaction score
690
Location
Dallas, TX
Should be the white wire in the cluster. Double check, there should be a wire coming off of the ignition coil, that should be white as well.

Sent from my SM-G965U using Tapatalk
 

laidbackbigun

I'm Awesome
Joined
Nov 30, 2015
Messages
561
Reaction score
278
Location
Oxford, PA
Its just weird cause these cluster came from running trucks. I work in a fleet scrap facility they did not bounce like this. My tach did not bounce. I put any one of these 3 in ky 95 tshor and they all get weird and bouncy and hover at 3k rpm
 
Top