Great.

Hey Joey -- I hooked up again and had the blinker signal going to the reverse trigger wire at the head and the monitor would try to come on - but the signal was not long enough. I will find ACC constant and use that instead. It should work and see the front /side camera when not in reverse gear.
However I ran into discussion that my 2012 Camry has pulsed speed signal to the head and can't be disconnected (not sure why -cruise control?-- I don't have navigation and gps--could I put an off on switch on the speed wire?)
If you have time appreciate your thoughts Thanks Roger

You need to tap into the turn signal wire from the arm. The arm switch grounds the power to turn on the blinker.

The speed signal would be pulsed as the speed sensor generates this. Would assume the radio is designed to accept this signal as a condition of cars movement.

Read post at link below:

{MOD} Navi/Phone Lockout BYPASS & Backup Camera on anytime - Toyota Nation Forum : Toyota Car and Truck Forums

Joey I just had not found that link --nice! Thanks again. Roger