This what i got from web site astinagt.com about installing RSM.
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This time, I found a much better time to wire it which I thought I'd share with you in case someone finds it useful one day.
The RSM needs 4 main wires , rpm, speed, ignition power and ground.
Power and ground are easy, Ive had a ignition triggered circuit setup for a long time to run various things.
The Apexi wiring guide says to splice the rpm and speed wires at the ecu and contains a manual with heaps and heaps of car's ecu pinouts. As per usual, the BA isnt mentioned and so with the last car I worked out the pinouts with the help of a mazda service center.
Anyone who has seen the ecu plugs knows this is an absolute pain in the ass!
This time I had the workshop manuals as a reference and worked out that the dash dials are a much better source of the rpm and speed signals. In the case of speed , it gets the pulse first, and then sends it on to the ecu.
The dials are also 100% easier to get to and work with.
What makes this even easier is that on the back of the dials is a plastic circuit board which is very well labelled and has screws inset.
Fantastic ! no cutting / splicing / soldering at all required. I just strip a bit of shielding off the RSM wires and use the screws as terminals to the circuit board. easy as pie and took like 10 minutes.
unfortunaly I didnt take photos although I meant to.
from memory the pinout of the dials is 2E is speed output ( to the ecu ). I think it was labelled 'SP+' on the circuit board. The RPM output was 2D I think. It was labelled something like 'P' maybe.
Either way, i connected my wires to the screws labelled 'OUT' behind the speed and rpm dials. Since the dash also has ignition triggered power, i used it to make install/uninstall easier. It came from screws connected to B+ and -
If any1 has a photo of the back of the dials cluster I can point out which I used.
So if ever u need a speed or rpm signal, use the dash, not the ecu
