Thanks SNAKEWOLF. I'm working from the installation instructions that shows the back up signal wire is in a cluster of wires coming out of the floor board, I just haven't been able to find a GY/YL wire in that cluster. Hoping someone has done this installation and can tell me which wire it is, I suspect it may be colour coded differently. Also, I found a post tfrom forum member alfdoc that says the Nav unit works OK without the back-up wire connected. Can anyone confirm this?
https://www.crossfireforum.org/forum...&highlight=nav