merc 150 6cy so I put a led light on the console,the light flashes when you first start the motor like is should do,so I know it works,Last time out the light came on steady,slowed the boat down light went off.My question is this light set up going to be accurate,can I depend on it?

Is it hooked across the buzzer so it lights when the buzzer goes?

yes

The light is just as good as the warning horn I have put a bunch of red lights in boats for that reason of not being able to hear the horn.....OPTI

I agree.

thanks, youll set my mind at ease

I couldnt hear my buzzer either, ended up putting a light and a new buzzer in.

https://www.amazon.com/gp/product/B008OTO2RG/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

This is the buzzer i used and its much louder than the stock high pitched one.