help testing s14 tach

[mcdenmon]

I'm trying to find a way to test my tach signal on my 97 240sx ka24de. I found all the pins. Can I use a multimeter, pos to signal wire and then ground the other to get signal? Please help I've been searching all morning.

[mcdenmon]

Pretty much what I'm asking is if I connect the positive probe to the wire coming off of pin 3 on the Ecu and ground the other probe, the voltage should change with engine speed correct? If so can someone please tell me about what voltage I should be getting. If not then someone please tell me a good way to test the tach signal.

[IanS]

http://www.nicoclub.com/FSM/240sx/ Pick your year, and download the factory service manual.

There is information in there on the testing of, and proper reading for all the gauges, including the tach.

IIRC, the tach will run off Hz, not Volts. So you will need a multimeter capable of reading Hz.

[mcdenmon]

]OK ill try to test it later then. Ended up going with a temporary fix. Added an aftermarket tach. I'd post a pic but can't quite figure out how