Tachometer install

Nicky · Force Sensitive Joined: 27 Mar 2019 Posts: 13

Hi. I would like to install a rev counter in my 67 split. It has an 04 powered Subaru engine. Does the signal come from the ecu? If so how do I find it? Any feedback would be greatly appreciated. Thanks

Kai · Posted: Sun Mar 31, 2019 3:53 pm Post subject:

Hi Nicky,

Are you using the stock ECU?

If so what engine are you running?

Essentially yes, the tachometer signal does come from the ECU, one signal wire, simples.

However we need to know the engine type to work out the ECU, to work out which pin you are required to connect.

What rev counter are you seeking to use? Ideally a 4 cylinder tachometer to suit your 4 cylinder EJ engine???

Hope this helps.
_________________
Think......

Don't sleep and drive!!!

Nicky · Force Sensitive Joined: 27 Mar 2019 Posts: 13

Hi kai
The engine is a ej20 2 litre from a 03 Subaru forrester I believe. It’s a fellows speed shop conversion which I Was told a renound conversion specialist. I purchased the vehicle post conversion. On the paperwork it says the engine is a T795 290751. Would that be the model and engine number?
I have looked on bussaru website and found the ecm pin out information but when comparing to my ecu it doesn’t look the same. Am I missing something?
The rev counter I’m hoping to purchase is a 52mm r-spec performance tachometer as I have a spare socket next to the temp gauge.
Your feedback would be massively appreciated as I am unsure on what to do next. I’m gussing the ecu is stock.

Kai · Posted: Sun Mar 31, 2019 7:37 pm Post subject:

Nicky · Force Sensitive Joined: 27 Mar 2019 Posts: 13

Hi
It says 4Q on the ecu. I’ve taken a picture but unsure how to post. Any ideas??

Kai · Posted: Sun Mar 31, 2019 11:03 pm Post subject:

Kai · Posted: Sun Mar 31, 2019 11:09 pm Post subject:

Assuming yours is a SOHC with a four plug ECU......

Connector B134, pin 10 is the Subaru tachometer signal wire output you want to connect to your tachometer signal input.

https://cardiagn.com/engine-sohc-2003-forester/

ECU wiring diagram is on page EN(SOHC)-22

Hope that helps.
_________________
Think......

Don't sleep and drive!!!

Nicky · Force Sensitive Joined: 27 Mar 2019 Posts: 13

Hi Kai
Thanku for that. Greatly appreciated. I’ll let u know how I get on. Thanks again

Nicky · Force Sensitive Joined: 27 Mar 2019 Posts: 13

Had a look at installing the rev counter this weekend. I have a spare socket next to the temperature gauge which is where I would like it sited (next to the water bottle). When I took off the blanking plate a noticed 3 spare wires with spade connectors on the end. I thought I would investigate to see if they had power. I put a voltage meter on two of the wires instead of just trying 1 and putting it to earth. Don’t know why I did this😬. Now I’ve blown something as my temp gauge doesn’t work and the spare wires now have no power. I’ve checked the fuses I have near the ecu ... there fine. Do u think I’ve blown something in the ecu?? There is a relay near the ecu and a couple of cylindrical items. I have no idea what they are. The van still works but somethings not right. Any ideas/feedback would be greatly appreciated ?? Very upset and frustrated🙈

Kai · Posted: Sat Apr 06, 2019 6:59 pm Post subject:

Sounds like you put an unfused live straight down to earth??? But in saying that as you’ve lost power to those 3 wires and the temperature gauge a fuse or wire may have blown.

I would be tracing the wires to the temperature gauge, don’t worry the temperature gauge signal wire is independent from your ECU which will be fine. Perhaps you found an previous tachometer wiring.

The cylindrical relays sounds like your Subaru fuel pump relay. Usually there is a square brown one which is the main Subaru ECU relay.

Your so close to getting this done. Keep at it

_________________
Think......

Don't sleep and drive!!!

Nicky · Force Sensitive Joined: 27 Mar 2019 Posts: 13

I spotted the ecu relay.
Am thinking you may be correct and I came accross a tachometer wire and possibly a voltage meter wire. Wouldn’t surprise me if fellows speed shop leave these wires in place when they fit the wiring harnesses.i could have possibly put the two together.🙈
I hope I’m wrong. I’ll chase the wires and hopefully come across a fuse🤞

Nicky · Force Sensitive Joined: 27 Mar 2019 Posts: 13

It’s been a while. I’ve been working away so time spent on the bus has been limited. I traced the wires back and found a blown fuse. Replaced it and all was good again. No damage done.👍 Managed to find the correct pin you mentioned. Wired it to the tachometer, found a switch live, earth and even a dash light live. All wired up and tachometer works great. Was shocked as things unusually go right for me on the first attempt. Am very grateful for the information you provided. Thanku.
My next job is to install a an oil pressure gauge. Will have to do some research before attempting this!!