Stereo problem. stereo turns off then back on when turned up past 28 or 29

c.parry95

Cadet
Joined
Jul 11, 2014
Messages
9
I have an 01 marada deck boat with a chevy 305 with one alternator and one deep cycle marine battery. I just replaced the stereo that was in it with another song because I did not want to change wiring. The problem is when I turn it up whether the boat is off, idling or at full throttle the stereo does a quick power surge when you turn it up loud. I put new speakers in that are very capable or handling the max volume from the stereo. There is no distortion or anything in the speakers when I turn it up to the point where it cuts out. It's just so frustrating when I want to turn a song up it just cuts out consistently until I turn it back down. I have read many different posts about this and many people say I don't have enough power from the battery or the alternator. .. but is that actually the problem? I also read about someone running a new ground from the stereo straight back to the battery. Would that work? Or has anyone had this problem and fixed it. It was also doing it on my old Sony stereo. Any help is greatly appreciated. Thanks
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,454
How did you hook up your power and what gauge wire are you using? Measure the voltage at the power and ground wires where they enter your unit and see what it is dropping to when you turn up the volume.
 

h2odick

Petty Officer 2nd Class
Joined
Jun 11, 2012
Messages
194
I had similar issues with my last amp, the stereo would cut out completely when turning volume up above ~36 with engine running, and ~38-40 with engine off. What was actually occuring - I was hitting the wattage output limit of my amp. Older amps would allow you to send a distorted/clipped signal to your speakers. A lot of newer amps, including mine will shut off @ their max rated wattage. I verified with a DMM that my speakers were getting the maximum 80W per channel (RMS) that the amp was rated for. Once i turned the volume up passed that point, the amp would cut out in order to prevent sending a distorted signal.
For me, this was volume level "36" with engine running (alternator running, more input voltage to amp, class d amp without fully regulated power supply.), and ~38-40 with engine off (because of the lower input voltage, the volume technically would have to be turned up higher to reach the same max output from amp).

If you have a DMM (voltmeter), verify AC voltage being sent to speakers at the max volume level before your amp/stereo cuts out. Convert that to watts and see what ya get. In any case, definitely make sure your grounds are in order, and the wiring gauge requirements for your amp are met (with length of wire run taken into account..)
 

c.parry95

Cadet
Joined
Jul 11, 2014
Messages
9
Wiring to the stereo has never been touched. The boat came brand new in 2001 with a Sony stereo so instead of rewiring I have only purchased Sony stereos. Will try out your tips and let you know. And also there is no amp? Or is it built in somewhere? Thanks for the help
 

midcarolina

Chief Petty Officer
Joined
Jul 16, 2013
Messages
631
I think Bruce is on the right track, the head unit has internal protection and is either shutting down due to low voltage......you either have a bad connection on + or -
too small gauge wire or bad battery
 
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