So I have a 99 gauge cluster with tach, but since im running a 2000 ecu, want to TRY to see if splicing my tach wiring coming from my ecu into the cluster to see if i could get it to work. Might be a long shot since the rpm runs off the bcm in the 2k+. I just want to try.

So does anybody know what color wire off thhe stock tach I could try to tap into?










~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ

Nope, but in for info....

I thought Fetter told you to take if off the PCM...but what that for external tach?




PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO

I get the tach reading for my shift light from the ECU. Wouldn't you want to do the same?

do not think the BCM controls the tach signal.

On my 2001 I had a open pin that I spliced into. I got this info from Fetter in a post on here.



FU Tuning

Yep guys that is the one I tapped into on the pcm, the open pin Fetter and Gary were talking about. That is used for my small tachometer. I just figured if my wire that is ran from my ecu to my aftermarket tach and it makes it work, why wouldnt it make the stock tach work if I spliced into it?

I heard that the tach and coolant are ran off the bcm, that is why mine doesnt work because I do not have a BCM in my 97.











~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ

I thought that the tach signal comes from the ECU as part of the datastream, just like coolant temp. The speedometer has it's own input, but it still has to run through the ECU first.





i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick

WHITECAVY wrote:Yep guys that is the one I tapped into on the pcm, the open pin Fetter and Gary were talking about. That is used for my small tachometer. I just figured if my wire that is ran from my ecu to my aftermarket tach and it makes it work, why wouldnt it make the stock tach work if I spliced into it?

I heard that the tach and coolant are ran off the bcm, that is why mine doesnt work because I do not have a BCM in my 97.

Ok so you are wanting to splice the signal from the ECU to also power your dash tach correct?

So you need to know what wire to splice in the cluster?

hmmm



FU Tuning

lol yup John, exactly.










~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ

I'll look into this for you, but I'm not sure if the 99 cluster is able to do this... it may still be Class II data line controlled...

For future reference, any data displayed on the cluster is controlled by the cluster, the bcm does not drive anything, it simply comes in on the class II line and is interpreted and displayed on the 00+ cluster. Where people get confused is that the data line runs from the pcm, to the bcm, to the cluster or from the pcm to the EBCM to the cluster... both paths are correct and accurate... so technically by the previous logic of the BCM telling the cluster what the vehicle speed is the EBCM could also "drive" our tach. This is not the case. Any powertrain info the PCM puts on the data line... body from the bcm, chassis from the EBCM.



Buildin' n' Boostin for 08' - Alex Richards

Interesting, so if the bcm has nothing to do with it, I should be able to run a 00+ digital cluster since I have a 00 ecm and engine wiring harness?

But, I still have a pre 2k interior harness.










~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ

You can also get the tach signal from the fuse box under the hood.Theres an empty slot with a spade terminal i believe.When i had an aftermarket tach back in the day,thats where i got the signal from.I spliced it in the wire loom going to the fuse box.Its a white wire i know.


Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust

^^ Thanks for the info man










~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ

How expensive can it be to pick up the right one from the local junkyard? I know it's $14 from my local junkyard.

The right what??










~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ

WHITECAVY wrote:Interesting, so if the bcm has nothing to do with it, I should be able to run a 00+ digital cluster since I have a 00 ecm and engine wiring harness?

But, I still have a pre 2k interior harness.

As long as you get the purple network wire from the cluster hooked up to the purple wire coming from the PCM you should have communication. But pre 00 I'm not sure.



Buildin' n' Boostin for 08' - Alex Richards

Come on, just man up and do a full harness swap. I did it not that long ago. It wasn't that bad.


"Oil Leak ? What oil Leak ? Oh, Thats Just The Sweat From All The HorsePower!!"

^You talkin about interior harness?









~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ

Bumper to bumper 00+!


"Oil Leak ? What oil Leak ? Oh, Thats Just The Sweat From All The HorsePower!!"

Oh ok.










~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ

Its easy to do. Everything is plug and play. You will need to modify the dash a little to hold an 00+ cluster and will need a new harness adapter for the radio.

Only thing I have found that I don't think works right is the fuel gauge. The ohms are different between the years. That's another easy swap though.


"Oil Leak ? What oil Leak ? Oh, Thats Just The Sweat From All The HorsePower!!"

Yep the fuel stuff would be easy. I know all I have is the time, so I may give it a thought.










~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
328 HP
306 TQ