Originally Posted by bluecoupe

I'm in the middle of switching to an OEM Nav unit and need advise, please. I was not so lucky as to have my car pre-wired so I have to install the jumper wires. No problem with the speed signal wire but I'm having difficulty identifying the back-up signal wire. Following the instructions I've located the cluster of wires and need to splice into the GY/YL wire. To me this means I need to find the grey wire with a yellow stripe. (The reason I think it's a grey wire with a yellow stripe is because the speed signal wire is green with a white stripe and the instructions label it as GN/WT.) I find there are 4 grey wires in the cluster, one has a red stripe, one has a black stripe, one has a green stripe and one appears to be solid grey. Uhm, so I think maybe the instructions are wrong so I go to the Manual and sure enough the back-up signal wire is GY/YL, so this makes me think the instructions are correct, but I'm no closer to solving my problem. So has anybody else run into this problem or could it be just my poor eyesight? Is there any way to test the wires to identify the back-up signal wire? Thanks...........