Where is the easiest place to tap into VSS wire for GPS/NAV install?

[thejeepdude]

I've got my AVIC-N1 about 90% installed, but I still have to connect up the VSS connection. I found a website that said to tap in on the ECM connector near the passenger fender and the shock tower. They must be talking about a gasser or something, so I'm not going to trust their wire colors either. I don't want to have to run it all the way under the truck to pick up off the RWSS. Anyone have a wiring diagram of an 2004. 5-2005? I have the '03 wiring diagram and it doesn't say anything about the VSS wire color or location(s) as far as I can find... someone help! :{



On a good note... this head unit is awesome so far!

 

[Matt400]

Hrmm, I find that odd. Why do they want the VSS input? I have a simple hand held unit that tracks speed right along side the vehicle speedo. Are other hardwired GPS units like that?

 

[thejeepdude]

Yes, they are all like that. It's more accurate to have both, especially when you lose satellite covereage. So, anyone know the easiest place to tap???

 

[Matt400]

Oh, I see.



I know your ECM now doubles as a PCM and I have a separate PCM. If your truck uses the same wire harness as mine it may be similar. Take a look at the Engine ECM mounted on the left side of engine block. There are two connectors plugged into it.

The larger of the two is the 60 way connector and pin #22 is the speedo signal on my truck. It is a white wire with a tan stripe. The connector is marked.



Maybe someone with a newer diagram can confirm if your truck is the same.

 

[thejeepdude]

found some more info...

That is the wire I saw quoted somewhere else... but I don't think that is it on my truck. I was just looking at the 2005 wiring diagram on the bodybuilder website and all they talk about is a SENSOR-SPEED OUTPUT and a SENSOR-SPEED INPUT... VSS or "vehicle speed" isn't contained anywhere in the FSM. However it appears the speed input sensor is only listed under the RFE heading (non-CTD). Under the RE heading there's just indication of a 2 wire connector on the transmission... check out the attached pic. . does this look like the one? I think I'm going to try it. . doubt it will hurt anything if that's not it. Dark Green and Brown...

 

[Matt400]

What you are looking at there looks like the VSS connector on the trans. That should work fine too. Maybe just unplug it and drive to see if the speedo is inop first before splicing in.

 

[thejeepdude]

What you are looking at there looks like the VSS connector on the trans.

Yeah, I know. . it appears as tho the connector on the axle is a twisted pair cable and not something I would want to tap into (unlike my '99). This particular circuit (the one I posted above) is located only at the transmission and at the ECM, which I'd be more leary about disturbing. The FSM also lists the transmission as the correct splice location for this circuit. I am going to give it a try today and let you all know what happened...

 

[rbattelle]

Oh, I see.



I know your ECM now doubles as a PCM and I have a separate PCM.

Really?! Is this a change for 2005?

[sorry... I don't mean to get off topic or "hijack" the thread]



-Ryan

 

[thejeepdude]

No, that was a change for 04. 5. . the 600's use the newer ECM style.

 

[nickleinonen]

link to dodge's body builder website. from here you can download 2004 & 2005 dodge ram wiring schematics

 

[thejeepdude]

link to dodge's body builder website. from here you can download 2004 & 2005 dodge ram wiring schematics

Um, yeah. . read post #5. . that's where I got the pic I attached. Thanks tho

 

[thejeepdude]

I am going to give it a try today and let you all know what happened...

OK OK so I was a little slow, but yes this connector was the place to attach the VSS wire. It's been working perfectly, and gives me speed accurate to within . 1 mph.

 

[CIverson]

I tapped into this for my superlift truespeed. I think I have a post in the 3rd gen forum on which wire.



Ok, I searched, here is what I had posted. I think there are actually 2 wires that are the same color. If I can find the box later I will try and get the pin location on the plug.



It's located on the most forward (towards front) plug on top of the ABS controller. It is white w/ an orange tracer.