Boss BV 6656B radio read the manual first. no really
and look for batteries inside that are dead first. always this FIRST.
a car radio RIGHT, posted to computers, and is NOT.
the Radio will have 2 power sources, most times.
1: ignition on.. ACC.
2: memory. (this must go to the car battery , hot full time wire in harness)and fused
if not wired right this will fail.
boy finding the install manual is a pain on this BOSS, users manual is useless, for that.. zero facts there but click rules..

what does Grill system mean,? google shows Zero hits. why use that word, dash? mounted, you mean?
it has a remote so remove its battery if they are weak
any remote on earth can go NUTS, (low battery worse of all)

ok you can remove all power to the car radio, all wires, power.
then wait overnite and try it then. (a level 1 reset on any thing electronic if batteries inside those out too)
most car radios have no battery, but BOSS id never guess.


the power button on the RAD has long press mode. use that?
>3sec long. it states.
the yellow wire is memory wire, remove that to reset radio.
red wire is ACC./IGN on wire main power remove both to reset radio.
I think i covered all ways to fix this problem..
remove power
replaced remote batteries first. as is the case always, first.