Does anyone know where to terminate the signal wire for a tacho. I have my coil on top of the inlet.

The instructions say to connect the cable to the negative side of the coil but shows a coil & distributor setup which imprezas dont have?

Can I use the signal for the OE rev counter as my dash and all clocks have been removed for hillclimbing next season

 

i had this nightmare with my Autometer unit i got from the states. I ended up having to buy an add on for the electronic ignition system so that the tacho would work....

i hope my hard work figuring this out helps you sort it quicker.


Auto Meter


Autometer tachometer adapter 9117 items at low prices on eBay.co.uk


How can I install a tachometer in my late model ignition systems.

We are getting more and more requests for tach signal wires and connection points on all kinds of new vehicles, and virtually every new vehicle has at least a DIS (distributorless ignition systems, or coil pack as it is more commonly referred to). The days of the "old distributor and coil" are gone, friends. This is a whole new ball of wax. The automotive industry appears to be shifting toward an even newer ignition system - C.O.P. This stands for coil on plug ignition system, which consists of attaching a coil atop each cylinder's spark plug, eliminating any coil pack, distributor, or plug wires. The computer for the vehicle controls the targeting for firing the plug when needed, supplies the voltage to the coil to discharge, and has a "monitor" to ensure that the coil did fire and at the appropriate time.


Ok, now you're asking your self, "What does this mean to me?" The answer: if you have a late model vehicle (most '99 and newer models) with C.O.P. ignition, it has everything to do with you.


We have had much success installing tachometers on c.o.p. ignition systems on late model vehicles where no available tachometer output is available. There are still some vehicles out there that have a useable tachometer signal, but for those that do not, all is not lost. We offer a tachometer adapter, model # 9117 which is universal to allow most vehicles without a tachometer signal to have a tachometer installed. For the installation of the tachometer adapter, it will require locating the power supply to the ignition coils and cutting the power supply prior to the power splitting between all of the coils. The tachometer adapter will have an in (red) and an out (red/green) wire. Wire the adapter between the two cut halves of the power supply. Ground the black wire and the last wire (gray) is your new tachometer output.


This is relatively easy on most vehicles, but depending on how the system is wired, you may be able to isolate the power to only half the coils. Chrysler V-6 and V-8 engines with individual coil on plug ignitions can be much more difficult, and you should contact our tech support department before installation on one of these vehicles.


This leads us to the next point and question, "Why can't I just splice into the wire(s) that goes to the tach in the cluster?" This sounds like a viable option, but the signal to the cluster tach is not the same signal as what our tach needs to see (12v square wave). This is commonly referred to as Multiplexing, which is the process of communicating several messages over the same signal path or wiring.

 

Thats great, thanks for the info.