tacho wiring for sr20det

[guidos]

dont worry about what i was asking, that answers my question for me

so having the light hooked up to ground and the tacho signal i should see the light flash i guess?

same for the CAS signal too then?

[THE ASH]

yes, you should

[Skanka]

sounds as though your ecu isnt putting out the signal - mine was wired to power, earth, and ECU pinout 3, no drama's - your problem doesnt lie in the wiring then, I would check your ecu for any errors, and see how you go with the test light,

[guidos]

ok, i'll check for errors. the list of codes is on the site above, but what is the test 'procedure' (ie with the VL you have to go in and out of Neutral, push the accelarator to the floor etc). and how do you put it in diag mode? same as the RB30 with the idle speed adjustment?

[D0ri-m0n]

i have tryed hookin teh tach up to pin 3 on my ECU but summin isnt right no signal so i tryed it with another workin ECU from a car at work and still no signal, that is why i am lookin for a wy to hook directly to the engine. i h ave tryed goin from the ignition module and i get a pulse thru my arm but teh test light shows constant light?? any ideas?

[PL]

Guys,

You might want to try using a pull-up resistor. The OP from the Nissan ECU is a +5V pulsetrain. I suspect the Autometer tacho needs a +12V pulsetrain. Some tachos will work OK direct from the Nissan ECU, others require a pull-up.

You can fix this by simply hooking up the tacho to the Yell/Red wire as described previously, and then connecting a resistor from this line to +12V. This will give you the +12V pulses for the tacho. A 10Kohm 1/4W resistor should be fine. If you're not into electronics all you need to do is go to your local Dick Smith/Jaycar/Force Electronics store and ask for a "10Kohm, 1/4 Watt resistor". It should cost you less than 10c.

I'd be VERY surprised if your tacho didn't burst into life after doing this.

Enjoy.
PL

[guidos]

so, the signal wire on the tacho is connected to the ecu's yellow/red wire as well as the resistor, and the other end of the resistor goes to +12v??

Dont wanna stuff it up

[PL]

You got it!

PL

[sixworks]

Tacho's & Tacho Boosters

Be aware there are essentially two types of tacho's; ones that operate on low voltage (12 volts) and ones that operate on high voltage (typically 200 volts). Many factory tacho's that were originally used with a distributor and coil require a high voltage pulse to drive them.

There are exceptions of course; VL Commodore and R31 Skyline being two cars originally using coil and distributor that will also work on 12 volts. I should also point out that nearly all aftermarket tacho's these days are designed to work on a wide voltage range; some even as low as 5 volts.

To test what type of tacho you have, simply connect power and earth as per the manufacturers instructrions and then 'flick' the signal wire onto a 12 volt source. If the needle moves you have a 12 volt tacho, if not, then most likely it is a high voltage unit.

To cater for both needs we sell Tacho Boosters that will safely boost the Nissans 5 volt signal to either 12 volts or the higher voltage required by factory tachos. Our website is soon to be launched however in the meantime please email us on sixworks@optusnet.com.au and we will be happy to send a technical information sheet.

Grant Blundell
SIXWORKS - innovative efi solutions