Do a search in the Audio/Electronics section. I posted it up some time ago. You can get it from the odometer's plug.. just can't remember the wire color right now..

 

yeah, I would love to know that too!

 

it's the black one with white stripe

 

dont quote me on this but i think john reed told me you can get rpm signal from the crank sensor wire going into the ecu; pin 27b
but more specifically he made me remove a wire i had spliced in there and said "theres other/better places to get the rpm signal from"

odometer wiring sounds like a win location though. i hate peelin up the carpet

 

One option is to use pin 58 off the ECU (IGF). This should be a red/yellow wire.

 

Thanks folk! Awesome!

Fred

 

What happens if u cut the wire ? ( hoping the answer will be no more 6800 rev limit ) !

 

your still functioning rev limiter will laugh at your non working tach

 

The electrical wiring diagram service manual is your best friend! The RPM signal from the odometer is called TACO (tachometer out I guess). You can connect to it by splicing to pin 29 (Black-White) on the II1 connector located in the right kick panel area. II1-29 normally connects to the stock ECU at pin 16A. If you're hooking this up to an AEM, add a 1K pullup resistor to +12V. II1 is an orange colored 38 pin connector. Should be easy to find.

 

Jim,

If I needed a 0-5v digital RPM source, would I need the pull up resistor? I need to find a 0-5v digital RPM source to trigger a circuit I am building. Assuming 0v = 0 rpms and 5v +/- = 7000rpms or something like that. I wasnt sure of the Tacho output was a 0-5v digital or pulse or whatever. My Innovate hooks up to the Tacho signal as a 0-5v source and it appears that works OK. Although it has a RPM range of like 0-10340rpms or something like that.

Stu

 

Old thread but I'm looking for the same answers as I am wiring up my innovate scg1. Does same wire from ecu apply to this set up? It also has 10230 vs 20460 scale. Then there's the pulses per rotation. Some guidance would be great. Everything else is hooked up minus the boost controller.

 

It is a pulse.

 

Thought so.

 

is the pin 58 igf wire also pulse? I have tapped into that wire for my innovate and it gives me some variations here and there. maybe i should be tapping into the tacho wire A16?

 

Use TACHO

 

getting that A16 pin from the harness was a BIZNATCH! anyways, perfect with innovate.

 

I had a similiar issue when my AEM v 2 was hooked up. I had an aftermarket RPM tach that stu installed with LEDs. Not reading any RPM. My harness is stock and never modified but the tach is not reading currently.

Is the solution to run a separate wire from TACHO to the RPM tach?

 

I would use only the TACHO signal to ECU-16A for anything that requires a signal for RPM. I also use it for a speedo conversion box from digital dakota and never have had an issue.

 

Is ECU 16A in the cluster? I was thinking the wire splice should go from the TACHO wire in the ODO to the RPM cluster?

 

No, 16A is the pin # on the ECU, but the wire from 16A does connect to the tachometer on the instrument cluster

 

Wouldnt it make more sense to just run the TACHO to the cluster?

I'm a newb at wiring so i'm a bit confused.

 

Just wondering if this is correct, I tapped into the rpm tach wire and my innovate says my auto shifts at 6350rpm. I had read that obd1 rpm signal is limited to 6250 or something. Anyone notice their obd1 rpm signal not giving past low 6k?