Anybody know what to hook into to get speed information for a nav unit?

 

I thought the navigation systems calculated speed based on the global positioning satilites. That being the case, no connection to the cars system is necessary.

 

The person doing my install was looking to tap into a vehicle speed sensor, of some sort.

There is a sensor on the transmission not far from the drive shaft; but since the mustang is so new, the info is not available of where to tap into.... which wire, perhaps.
Regarding the gps/speed; I guess the satellite is position, and with speed there is a more finite calibration.

Just guessing though.

Hey, if I knew how to get around things, I wouldn't be putting in a gps. lol.

 

I have a portable GPS from Garmin that I take from vehicle to vehicle without any connection other that power. In addition we use the system for calibration of the Ski Boat speedo's for ternimite skiing.

The GPS I have is acurate to with 15 ft of actual location. They might be using the connection in case you loose sight of hte satalate in a tunnel ect to estimate the distance traveled. Mine just indicates lost signal and then resync's after I return to a area where it can recieve the satalate signal

 

No offense, but if the installer can't find it, maybe he is not qualified.

Most, if not all, stereos cannot use the raw digital feed from the tranny. It is filtered before it even operates the speedo. Most cars, including your Mustang have a seperate speed signal that can be used. This is the same signal that is tapped into by the speed sensitive volume on the Shaker 500 and Shaker 1000.

I would bet there is a wire right there behind the stereo (I am guessing you have the base radio) that is obvious to a professional installer.

If you have either Shaker, the speed signal is already there into the back of the unit.

 

Thanks for the expert advice although I have already found out that it should hook up to connecter C138 pin #25 of 50 pin. Brown/green wire. It's a pioneer thing for accuracy.

 

Personally, I left out this part on 7 of the 9 I installed. Most people don't want more additional wiring added, so this step is usually bypassed with the S197. It is easy enough to add, and runs into the J1 plug of the head, to the #17 pin of this block.

I've installed numerous Ford Navigation heads, and in my steering wheel controls write up, we discuss the VSS port. It is only a small section, but it does cover this.