lowrance turns on then shortly turns off again.

very frustrating anyone have an idea of what I should do or why it's happening?

I would check with a meter to see if it is getting proper voltage from the battery.

Could be low voltage to unit....or could be too small of wire to power source.

Has this Lowrance worked correctly in this boat before?
Or is this a new installation?

is it turning off or is the screen going into night mode?

What model?

I had a similar problem. Used the power button to turn it off. Problem is the power button controls the display brightness.
The unit would turn on and the display would go dark after a couple seconds.
There is a way to reset the unit at turn on. I forget how to do this but I am sure you can google it and find it.
After you get it working again, use the touch screen to turn it off. Should fix the problem.

If the screen is black and and it actually is on....the brightness might be turned down..press the power button once and a display will come up like thisAttachment 413200 touch the brightness and slide it up.This is for gen2s-through latest model touch screens.