Tacho connection Coyote to Smiths
 

Hi,
As a few cars are built now using the Coyote, I am hoping that someone has a solution to the tacho connection for a 2015> Coyote 5.0 to a Smiths tacho on a superformance (cobra) i am helping a friend with.

The 2011-14 Coyote has a tacho output on the Ford controls pack however later ones (2015 on) do not. To remedy this an Autometer tach adapter can be used to create a tacho signal. Ths i have done however i am not getting a functioning tacho.

I have the dip switch settings on the tacho to what i think are correct being "00010001" which is 8 cylinder/8 pulse. Have also tried settings for 8cylinder/4 pulse.

The tach adapter is wired to the white/black input on the tacho.

Apprciate any clues that could be provided

Have you thought about running the tacho for 1 cylinder operation, dip 0000 0001, pick the signal from only one coil, and do away with the tach adapter?

I hate anything that can interfere with the ignition system, even including tachometers.

I've used the Autometer 9117 in a (Connecting to an Individual Coil Per Plug Ignition System) like Gaz mentioned.

Your just hooking up to one coil. Listed at the top of page 4.
http://www.autometer.com/media/manual/2650-561X.pdf

On the Tach, on the Smiths instructions if you are pulling a signal from one Coil pack the PPR for an 8 cyl = 4 or 1010000 dip swt setting
https://www.caigauge.com/documents//...-tacho-360.pdf

But thinking back,,, Since your pulling a single cyl signal the One cyl may be correct. PPR= .5 or 0000000.

I wired the adapter to the 12v + feed that supplies the coils (all 8) per Autometer detail for coil on plug.

The tacho model is RVC2816-00CB

Will have a look at doing a temporary wire to a single coil negative and set dip switches on the tacho accordingly to see what i get. I have read that that doing this way gives erratic signals but have not tested myself yet.

Have had another look today amongst other tasks.

I took a temporary lead directly from cylinder 1 coil neg direct to the tacho input (completely bypassing the adaptor).

The white/black wire did not give a signal however the red/blue did so continued with the red/blue – (The tacho instructions allow either to be used).

I now get responses from the tacho as follows.
“00000001” (0.5 pulse) dip settings gives around 7k rpm with a fluctuating indicator and then drops out to 0 rpm after 15 - 20 seconds

“10000001” (1 pulse) dip settings gives around 7.5k rpm with a fluctuating indicator and then drops out to 0 rpm after 15 - 20 seconds

“10100001” (4 pulse) dip settings gives around 4k rpm with a fluctuating indicator and then drops out to 0 rpm after 15 - 20 seconds.

“00010001” (8 pulse) dip settings gives around 2k rpm with a fluctuating indicator and then drops out to 0 rpm after 15 - 20 seconds = Also noted the tacho drops to 0rpm when applying throttle ………

Following the above pattern where indicated rpm is reducing with pulse change, I thought I’d try the following

“00001101” (12 pulse) dip settings gives around 1200 rpm with a less fluctuating indicator and finally,

“00110011” (16 pulse) dip settings gives around 950 rpm with a less fluctuating indicator. This RPM value is about right for idle whilst the car still in its warm up cycle.

The RPM continues to go backwards on throttle application though ????

Any thoughts?

I'm thinking the reverse operation would be a polarity issue but don't want you to smoke something on my say so.
I would call Smiths directly as you are getting signal response albeit 180 out.
So technically you're almost there...

This may be of help.
https://thefactoryfiveforum.com/show...hometer-hookup
https://www.svtperformance.com/forum...oyote.1035562/
On page 70 (this is Ron Francis wiring)
https://www.factoryfive.com/wp-conte...in-Hot-Rod.pdf
http://www.ronfrancis.com/images/CY15-INST.pdf

What engine management system are you using?
Perhaps the tach signal should come from there?

Gaz,
Standard 2015+, Ford Coyote ECU / controls pack designed for this year motor.

In any case, the tacho has been taken out and tested by an instrument specialist. The outcome of which is that the tacho is faulty and not responding to ECU inputs and inputs from coil negative are very unstable.

It ran good on alternator input so have set it up in that way temporarily until the owner can sort a replacement tacho from the supplier of the car.

As all the wiring is still in place, (apart from one solder joint) it will pretty much be a plug and play when a replacement is made available.

Sounds like you have got somewhere there Rick.