hardwired kit

[98 SNAKE EATER]

and it will be easier to use the piggyback fuse type hardwire kit.
like this:

I'm a little curious about the wiring on this kit....

On all of my previous installs, I used a basic 10amp LVC board like this:

What exactly does the 3 wire parking kit achieve by using an accessory signal (yellow wire)?

 

[Canon T-90]

when the engine is turned off the power supply with 3rd wire(yellow) sends a signal to camera which switches to parking guard function....which is user definable.

 

[98 SNAKE EATER]

when the engine is turned off the power supply with 3rd wire(yellow) sends a signal to camera which switches to parking guard function....which is user definable.

Ok, I was wondering if it dropped voltage or sumthin.
My plan is to run the camera constantly as I do now with my 0801, but still have the safety of not killing my battery