Tach Terminal Voltage

[matt82]

i do not have a multimeter and was wondering if somone could tell me what voltage in put out on the tach wire from an r33 ECU

thanks in advance matt

[PlasticStan]

i do not have a multimeter and was wondering if somone could tell me what voltage in put out on the tach wire from an r33 ECU

thanks in advance matt

<{POST_SNAPBACK}>

The ecu doesn't output a volatage on the rev counter output, it is an open collector that is pulsed to ground in time with the engine timing pulses.

[browny]

AFAIK the tacho system (tacho + ecu) works off a 5V square wave.

And as said above, the ECU end only provides the pulsing, not the voltage.

[matt82]

thank you very much guys

now the second question

if the pulse is only a 5 volt square wave

and my new tacho requires a 12 volt signal where do i het the 12 volt signal from?

or do i need an signal convertor of some sort??

[StockyMcStock]

just wondering if anyone had any ideas on this problem. my tacho doesn't work and i think this is why.