[stever975]

does anyone know what color the tach pin is on the ECM for the 2012 vrscdx? i tried pin 3 but it does not seem to be the tach feed.
Thanks in advance,
For a Raptor shift light!

Yes. It's pin #3 of the 36 pin ECM connector [78] as shown in this cropped image of Figure 1-4 on page 1-11 of the 2002 EDM (99499-02):

The only VRSC models that used this pin where the '05 & '06 VRSCSE and on these bikes the tach signal wire color used was pink (same color as used on all other HD bikes with a tach feed).

In order to use this on a non-VRSCSE model you'll need to disconnect connector [78], open up the [78B] Packard connector as shown in Appendix A of the service manual, attach a Packard socket terminal (72076-00) to your tach feed wire, place the terminal in the connector, reassemble and then plug the connector back into the ECM.

 

[stever975]

Here is a picture of my ECM. Pin 3 already has a black wire coming out of it. Do i piggyback the black wire with my tach feed? I am a little confused to add the new pin when one already exists.
Thanks in advance,:notworth:

Where does that black wire go?

Has someone changed the wiring?

I don't have a 2012 wiring diagram but all the others I have up to 2010 show no use of pin #3 on VRSC models except the VRSCSE bikes. The other wire colors I can see in your picture match the earlier diagrams I have.

If you have a digital multimeter that can read frequency you can measure the signal on this wire (referenced to the battery negative) with the engine running. At idle (1250 RPM) this should read about 21 Hz if it's the tach signal.

 

[stever975]

I have no clue where the lead goes to. I am pretty sure no one has touched the wiring, as i bought this bike new directly from HD and it only has 140 miles on it now.
I had a friend come over with a multimeter last night who is a mechanic. He has a meter that can read RPM and various engine setups and we tested the black wire and nothing but a little voltage showed.
This is sure getting difficult for a shift light.
Everything is complete but the tach lead.
Any other suggestions?
thanks

You need to trace that black wire and a 2012 wiring diagram would also be nice.

The tach signal is a 12 V square wave so only a small voltage will display on the DC volt setting. I can't imagine a mechanic with a multimeter that doesn't read frequency.

 

[stever975]

So here is the 2012 vrscdx ECM wire guide direct from harleys service manual. According to harley there is no tach output for me to hook in to.:chair: I find this impossible. It has a factory tach, and a rev limiter which means something is reading RPM. Anyone have any ideas on where i could draw a tach signal from? The coils are individual (front and back seperate pins). Any ideas.
Please Help.

It is also showing no wire on pin 3. Are you sure you have a black wire on pin 3?

I looked a little closer and see that pin #3 has been changed to a O2 sensor ground so you're SOL for a true tach signal. You can get a somewhat inverted tach signal from either of the coil trigger signals. These are the yellow with blue stripe wire (pin # 11) or the blue with orange stripe wire (pin #29).

BTW, the factory tach for VRSC models (except the VRSCSE) don't use pin #3. Engine speed is sent to the tach over the serial data line.

Sorry for all the edits but it took a while for me to think about this.

 

[stever975]

I have to disagree. Pin 3 IS listed half way down. I assure you that no one has modified this bike and added anything. I purchased this brand new, 0 miles, 3 weeks ago. The bike is stock.

So is it really impossible to hook up a raptor shift light on my bike? ther is no plane pink wire on the whole ECM. there are a few pink and (different color) but know straight pink.

I do appreciate the help.

Look at my edited post.