AutoMeter Tachometer Signal - 4.6L Ford

[BM1]

Is a tach adapter needed to hook up the AutoMeter tach/shift lights in these cars? Or, could I follow the Raptor shift light procedure and splice into the same PCM connector wire and use that?

AutoMeter states that you MUST use a tach adapter, but I know for sure that the PCM has a tach output wire but I'm not sure if it's clean.

Here are the AutoMeter instructions for an '04 V8 Mustang:

"Tachometer Signal Wire Installation
for 4.6 engine(s)
Must use model number 9117 Auto Meter tachometer adapter. Locate the large, square 42 pin wire harness connector in the corner of the engine bay where the passenger fender meets the firewall. Pop the plastic cover off of the top of this conector to expose where the wires enter the connector and to expose the wire pin numbers. Locate pin number 34 which will be in the corner of this connector and will be either a red wire or a red with a green stripe wire. Cut this wire in half so that you now have two cut halves. Hook the red of the adapter to the cut half coming from the connector. hook the red/green of the adapter to the other cut half. Ground the black wire of the adapter. The gray wire of the adapter will now provide you with a good tachometer signal."

If we absolutely must use AutoMeter's tach adapter, would it be possible to stay out of the engine bay? In other words, does pin 34 in the 42-pin connector under the hood come in somewhere under the dash or have an identical hookup on the PCM harness?

I have the AutoMeter DPSS Stage 2 digital tach/shift light.

[Sukkoi19]

Most guys just tap into the PCM wire. You have to set it to .5 though since each coil fires twice for every revolution.

[MystiChrome04]

As Jamie has said the PCM wire is fine, no reason to spend more money on a tach adapter when you don't need it. Just make sure whatever shift light you've got that it has the ability to change the how it multiplies the tach signal. You can trace it out to a under hood wire (that's where I've got mine too for both my raptor and FJO MPC. I'll check it tomorrow and give you a call, can't remember which off the top of my head and the car is at the shop)

I am still waiting back on your price quotes so don't think I forgot about you Brian, I sent one e-mail to one of the sales guys and then another out to a different sales person there at Lethal, still waiting on them, if it's not in by tomorrow i will go elsewhere and still get great pricing. There just my first go to guys and this time there proving to be a little slower then usual.

[BM1]

Ryan,

Thanks for keeping me in the loop on that! I called you tonight but it went to voicemail.

Scratch the control arms and suspension off the list. Lonnie at StangSuspension.com cut me a very good deal on an Eibach/Tokico spring/shock combo. I also got ahold of Pro3i control arms at an excellent price. Keep searching for prices on tires, nitrous, and long tubes!



Jamie,

You're 100% correct on that. Thank you!

I actually found the answer to that before I read your post, but at least I know I have multiple sources of good information.

The answer I got was from the Mach1Registry was that another user had already contacted AutoMeter about it and got a response:

"I sent email to AM about this:

Can this product be connected directly to one coil drive wire (from ECU
to COP) and then set to 0.5 pulses/rev to work with the ford modular 4.6
DOHC?

Or does it require a tach adapter?

Thanks!
************************************************** ****

John

Yes you can hook the DPSS to one of the coils trigger wire and set the
DPSS for .5 PPR.


Auto Meter Products
413 W. Elm St.
Sycamore, IL
60178"

Therefore:

Can we safely assume that pin 26 or pin 104 can be tapped on the PCM connector? Pin 26 is coil #1 (LG/WH) and pin 104 is coil #2 (PK/WH). The Raptor shift light hooks up to either one of these wires with no adapter. Can I assume that I can hook my DPSS up to either one of these wires as well? I can then set the unit to .5 PPR if that is the case.


I believe pin 26 or 104 just as the Raptor uses will work just fine. The PPR will be set at .5.

Do you folks concur?