Anyone know the easiest location to pick up the speed signal for a 2003 Dodge Ram for an aftermarket GPS system? It isn't in the stock radio wiring harness is it? I think there is something there like a "data" line, anyone know what that is?

I guess I need to open the wiring diagrams and take a look.

I have a Pioneer AVIC-N1 installed and it works great, but I don't have the speed input hooked up yet.

 

Speed signal???
All my GPS systems (1 in boat and two port) detect speed by time differential between two points. No outside interference. What is the guarantee that the sender is accurate?

 

The reason for the external speed sensor is so it will calculate your position when you go into tunnels or other areas where you lose singnal. Some GPS's do an ineratil projection intil the signal is re aquired. Anyway thats what my son's does.

 

Correct. Not a big deal, it works well without it, just thought it might be nice to have in certain situations (tunnels, etc.). From skimming the manual it looks like this unit is very intelliegent with regards to using / calibrating with the speed signal. It determines how fast your going while you have a good GPS signal lock and then examines the speed input reading. After that it knows what the speed input signal actually means, no user intervention or settings needed.

 

Berak,

I picked up the signal for my Superlift Tru-Speed to recalibrate my speedo at a box under the hood right on the firwall on the drivers side - I cant remember what it was but, if you are interested and think this may help you then let me know and I will dig up the directions and can scan them for you and take a picture of mine for you - just one wire - let me know

Jason

 

I picked up the speed sensor on the driver's side of the tranny.. there's a twisted pair of green wires (can't remember the strip color) of which I tapped into one (one is ground, the other is signal). I just went through the hole above and to the right of the go pedal and down to the tranny. Once you have this hooked up, you'll notice the MPH reading on the AVIC becomes VERY precise! It's accurate to within .1mph and updates a lot faster than GPS alone...