Car data wiring to head unit.

Garffey said:

My Graphite didn't have a reversing camera GD....But now I remember the brown wire (marked 'back' on my Chinese loom) was for the reverse camera.
Also remember mine had to have a 'filter' fitted between the reversing light and the head unit as I got interference on the picture, which I assumed was due to the cheap Chinese head unit?

Click to expand...

Didn't realise you had a Graphite, that is what mine is so presume the same head unit. Thanks for the information.


You are correct is does not have a reverse camera and don't think the unit even had capability to fit one (unless it uses the AN-IN port) so I am dubious if this is correct, I got that information from a thread on an alternative forum and can not be sure they were talking about the same car model or head unit model however the car in question was a 2013 model (I've just re-read the thread and apears it was a Sport Tech) I was making the assumption that the wiring for the car would be standard for a given model year but obvioulsy I have a sample size on one for my assumption and everybody has the right to be wrong so it is in no way dependable.
Apart from when equipped with a camera I don't know why else the head unit would care about reverse.

I will check the connections when I take out the head unit to swap over as I'd like to confirm their function, I'd also like to know if they switch high or low.

However I do think there is a fair chance that these are simple 'switched' connections rather than a data stream (CAN type) which the METRA standard appears to indicate for these connections.

It's possibly worth mentioning that these 3 connections (including the pink) went to a port marked SENSE on the head, this port has 8 pins and all were wired into the sub/adaptation loom however the remaining 5 terminated at a green plug which was simply taped into the loom (unconnected)



Here I've highlighted the SENSE plug and the taped up cabling.

Seems like the head allows more signals to be input either as simple/switched signals or possibly as a data stream (or a combination of the 2), the problem is I can't find any information on this SENSE connection. This seems to be typical with this ICE stuff, every car and every manufacturer seems to insist on using their own connectivity rather than using a standard.
Rant over!

If the brown wire is not reverse I can't think what else it could be. What other information the head unit may use?
Maybe reverse camera was possible, there are spare connectins available on the AV-IN socket.