Alright boy/gals, you have all helped me so far with the bypass now I am ready to put it all together. There is two wires I cant figure out where or how to attach them. The car speed signal input and the reverse gear signal input. I am installing a reverse camera as well and it looks like these need to be hooked up. Where and how do these go?

Thanks for all your help and I am doing this as we speak so any quick response would be greatly appreciated!

it would help to know what kind of car your installing in

2003 ford expedition

alright I am back, have not got to the camera yet, but the bypass works and the radio. In the expedition we have a factory rear DVD system that i got the harnesses from crutchfield to keep that baby working. When i put a dvd in the back system i only get sound out of the drivers side speaker and none of the other ones. But when I play the tuner all speakers work. Where could the mess up be? Lastly is there a way that I can play the dvd on the avic and have it appear on the rear dvd screen as well at the same time.

Thanks for you help and responses!

I would love an answer on the speed wire as well. Another site I have searched on says it is in the original harness, only it is a gray/black wire but I am scared to hook it up and totally blow the system if that info is wrong. Also I have an aftermarket rear screen and it is connected with the RCA harness to the D3. Works great too! It even plays when the car is in motion and the brake isnt on. My next step is the bypass so it will play in the front too.

I would love an answer on the speed wire as well. Another site I have searched on says it is in the original harness, only it is a gray/black wire but I am scared to hook it up and totally blow the system if that info is wrong. Also I have an aftermarket rear screen and it is connected with the RCA harness to the D3. Works great too! It even plays when the car is in motion and the brake isnt on. My next step is the bypass so it will play in the front too.

the older models had it in the radio harness. you may still get lucky and find it there, as ford is not very consistent with their wiring. if not its here:

Speed Sense gray/black wiper motor or PCM

The PCM (Powertrain Control Module) is on the passenger side firewall. The VSS wire is in the plug closest to the fender, pin 13

and the reverse wire is black/pink in the drivers kick

Thanks alot! I had already searched for it and found the location on another thread with a link to www.rostra.com. It was great. And my Expedition is an 04 and it was in the radio harness still just for anyone else with the same question.

You guys got me confused, what does the speed sensor wire do and do i have to even hook it up? and are you saying that i have to hook up that reverse wire in order for the back up camera to work? Thanks! If i play the dvd up front i have no issues but when i put it in the rear dvd all i get is pic but no audio. the rear dvd is factory any advice on that????????

the vss isnt "necessary" but does improve the navi. if its accessible, i always hook it up. you need to hook up that reverse wire so that the camera comes on when you shift into reverse. as for the dvd audio, check all your connections on that adapter plug. as i said before ford is not very consistent with their wiring, that plug doesnt always work on every vehicle

if it has to do with the wiring is it possible since the dvd works on the D3 that i can get it to play on the rear dvd screen, kind of like a splitter on a tv?

no, there is no video on that harness. you would have to go inside the rear dvd player and splice an rca cable into the correct wires going from the video game inputs to the screen