Accessory wire during startup reboots radio

These aftermarket Nav units take quite a bit of time to boot. When I get in my car I usually turn the key to on, wait for the system to power up and then I start the car.

Anyone ever try wiring their radio to stay powered on during boot?

 

This would probably be fairly difficultly, and most likely not a smart move.

You’ll find that a large portion of the sensitive electronics in modern vehicles turn off during crank because the electrical system can often pump out more than 14.4v for a quick second and this can damage radios/chargers/cameras/etc.

 

It's not like the radio is isolated from the battery during crank so I doubt they're worried about over voltage on the radio; The alternator output circuitry should output the right voltage and burn off any excess power from the coils. I think they do it because the starter motor uses enough current to pull battery voltage down to ~9 volts. Its possible that the radio could survive for a few seconds off 10 volts or less. It's also possible to design a circuit that could hold the radio on, but I just wanted to see if anyone had tried first. Maybe I'll have to use a second battery and an isolator to pull it off.

The radio has enough power during crank to hold user settings so there is circuitry that supports intermittent voltage drops below 12 volts.

 

user settings are held by constant power.

Pretty sure accessory power is extremely limited during crank/start, if it isn't non existent.

 

Does anyone have a wiring diagram of the accessory circuit for a get 2? I don't think it's a matter of limited accessory power; I think they design accessory to pull low during crank.