Speedo Pulse

[jaysq]

Hey guys, can anyone tell what color and where I can tap into the speedo pulse cable. I'm having a h*ll of a time trying to track it down myself.I need the pulse to run a NAV unit. Any help would be great!!:eyecrazy

[Q45tech]

The speed sensor is in the rear transmission tail shaft, its weak pulses [variable frequency is translated by a module [rear of speedomter to zero to 5 volts] to fed the ecu, the tcu, the cruise control, the ABS, the air bag computer, and the steering pressure computer.

Careful with taping the shielded wiring!

[jaysq]

can i tap the wire going into the ecu? Or the TCU? I need some advice.

[Q45tech]

Tell us the website for the NAV unit, hopefully online manual!

[jaysq]

Its alpine's NVE-N851A. Alpine's site has the generic owner's maunual. I downloaded it... it asks for the speedo pulse wire to be tapped into. I just need to know where to tap.

[Q45tech]

My concern is that the unit may not like [function with] the extremely low level frequency from the Nissan speed sensor........before you go tearing up the dash.....the speed sensor socket at the transmission would be a good place to temporarily tap the signal......making sure it works with the Nissan sensor without additional amplification.

You might try terminal # 27 on the AT control unit as this [terminal from speedo module] varies between 5V and 0V --------pulsing with speed.

Careful when attaching any external devices as the systems were not designed to sink additional current. Study your FSM AT section.

[jaysq]

Just what I was looking for!! The Nav system does say it would be a low volt pulse that is needed. Thanks for the help.