Hi All,
Yesterday I decided to finally try and install my aftermarket dash in my s14.
I will also note at this point that I have an EVC 6 in my car hooked up to read the rev signal (pin 7) from the ECU.
The standard tacho was working prior to this adventure, as was the EVC rev readout.
When wiring in the aftermarket dash I had to obviously unplug all the standard dash plugs and splice some of the wires into the new display.
At some point in the japanese instructions they said to connect the engine speed wire input into the illumination wire!?!
So anyway at that point we started the car and neither the EVC nor the new dash displayed any revs at all.
I disconnected the new dash and started troubleshooting. After tracing the circuit on the back of the standard cluster we found the correct tach wire on the dash plug and spliced it in.
Still no reading on the EVC or the new dash.
Found another manual for the dash online and read that the tacho requires a -ve switching pulse instead of the +ve switching nissan has out of the ecu.
This doesn't explain however why the EVC is no longer displaying revs. I believe the signal out of the ecu is +5v switching signal.
Does the standard instrument panel have a pull up resistor in the tacho circuit somewhere that converts the signal to +12v switching as this is the only thing I could think would be making the EVC no longer display revs??
I'm hoping it's just a case of needing the pull up resistor for the evc to read correct and then a transistor to convert the signal for the new tacho.
Any help would be fantastic.
Also we checked the wire from ecu across to dash for continuity, came back fine.
Cheers
Jamie