installing a tach

[Lewis Shadoff]

At 05:09 PM 12/15/01, you wrote:
>Subject: Re: installing a tach
>To: SE-R Mailing List Digest <se-r@lists.deskmedia.com>

>the archives say the pin coming out of the ecu to the stock tach is
>different than for an aftermarket. why is that? and how come i can't hook
>them up together?

The output of the distributor is an AC signal whose frequency is
proportional to RPM.  In the '97, the ECU converts it to a DC voltage and
sends it to the tach.  Can someone with a 91-93 FSM check if this is the
case for these cars?

In many cars (including Honda) and almost all aftermarket tachs, the signal
to the tach is an AC signal, and the tach has a frequency to voltage
converter built in.

Lew

Lewis Shadoff
Lake Jackson, TX
'97 200SX SE-R, Level 10 Auto, HotShot turbo
http://www.brazosport.cc.tx.us/~lshadoff/turbo/