Reverse wire that triggers factory radio back up cam

[TahoeLT10]

Long story short, factory backup camera to my Pioneer HU that I had for 6 years stopped working. After much troubleshooting, I came to conclusion that it is the HU to blame as everything works fine with factory NAV (more details in another post on here). Anyways, while everything is working with stock setup, I now have front camera with nowhere to connect it to. I made home-made harness from factory radio harness to my front camera and backup camera via AV switcher ( https://www.ebay.com/itm/2-to-1-Channel-RCA-Video-Intelligent-Switcher-for-Car-/112692092202 ) to factory NAV with latching switch for front camera activation. All is working. However, all is working ONLY when shifted to reverse. I need to bypass to get front camera to work whenever I want to with a switch. Does anyone know what wire or what exactly triggers the factory NAV to switch to backup camera mode? I am attempting to bypass that with providing contact to reverse wire PIN on factory NAV to make front camera work (at least that's the intent). Thanks.

 

[drakon543]

probably the reverse light power signal. you can wire a diode into the signal wire now and add a switched 12v source on the radio side of that switch. when the switch is on it will stop the 12v from backfeeding to its original source signal. just make sure the diode is facing the correct direction. you can also add a nc relay onto the new switched signal with the relay trigger being the original signal source. that way if you forget the switch on and place the vehicle in reverse it will break the power from the new 12v signal. both of those will stop backfeeding and sending 2 12v signals into the same source.

 

[TahoeLT10]

probably the reverse light power signal. you can wire a diode into the signal wire now and add a switched 12v source on the radio side of that switch. when the switch is on it will stop the 12v from backfeeding to its original source signal. just make sure the diode is facing the correct direction. you can also add a nc relay onto the new switched signal with the relay trigger being the original signal source. that way if you forget the switch on and place the vehicle in reverse it will break the power from the new 12v signal. both of those will stop backfeeding and sending 2 12v signals into the same source.

This is pretty much what I have, but which one is reverse light signal wire? Stock camera harness has 3 pins, AV +, ground, and 12v on reverse, BUT... I noticed Metra's harness did not tap into 12v pin and I tested with my home made harness with 12v pin connected to the radio and without and the backup camera turns on regardless.

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[drakon543]

it's probably the av+. the Metra harness would most like give you 2 options for that signal. one would be when your starting off with no backup camera and your installing a hu and backup camera. the other option when your going to reuse the factory backup camera. factory backup camera will already have the trigger signal for it. without a factory backup camera there may or may not already have the wiring there for it.

 

[TahoeLT10]

Good point and I tested that, but no avail. Connected front camera that has AV + and ground always supplied, but the NAV did not turn to reverse.

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[TahoeLT10]

Well, stupid me. Forgot that I have AllData and Mitchel and both have the wiring diagram. Now I only need to make sense of it.

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[kbuskill]

Well, stupid me. Forgot that I have AllData and Mitchel and both have the wiring diagram. Now I only need to make sense of it.

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These trucks don't use a reverse lead to switch the HU to camera. It is done via the canbus data line.

Just FYI.

 

[TahoeLT10]

These trucks don't use a reverse lead to switch the HU to camera. It is done via the canbus data line.

Just FYI.

Thanks. Yes, that's what I concluded after tracing the wires by using Mitchel. Thanks

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