Electrical Problems

[Sundancer270]

I have a 1992 Sea Ray 270 Sundancer with twin 4.3L engines.

I started experiencing electrical problems last summer, initially my cigarette lighters quit working, then the stereo speakers stopped working, the port battery would not hold a charge even when at the dock plugged into shore power. I replaced 2 out of the 3 batteries, 1 on the port side and 1 on the starboard side. the electical problems continued. When I would get down to the boat on the weekend, after the boat sitting all week attached to shore power, I had to use the emergency start to start the port engine which had a new battery. Then the dash lights quit working.
I was wondering if part of the problem could be the converter and was hoping to get some idea as to what might cause this.

thanks

 

[Kevin Smith]

Electrical Problem

Sundancer 270,

It sounds like there are two different things going on, but not sure-so here is how I would approach this if it was a problem on my boat--

The most obvious problem that could cause the low batteries and the circuits not working could be a dead short that draws a lot of power and may or may not cause your breakers to trip. IE there is probably a hot circuit that has shorted out to something that is a ground it is likley allowing your batteries to drain down quickly and your charger is not keeping up??

First I would check the major cables (like the battery to starter cable could be shorted to something. a short of this type can suck out a lot of amps very quickly) in as many places as you can easily get to and you will likely find one that is melted or discolored where is has gotten hot. If there is some piece of equipment on your boat that is shorting out, it often is warm or hot to the touch. IE if the starter is shorted out it draws enough juice to get hot when the battery is fresh or warm if the battery is a little old. You can also try disconnecting equipment like hot water heater, fridge, bilge pumps, macerator, running lights, windlass, etc. Some folks would also disconnect the battery everytime until they no longer see a spark jump across from the cable to the battery. The lack of a spark is then a tell tale sign that whatever is drawing power is no longer drawing power. Because of the complexity of electrical circuits on a boat and the possibility of fire, this is not a recommended method.

Another way to try to isolate the problem(s) is to turn off breakers one at a time, wait a few hours or overnight and see if you batteries are okay. Assuming that breakers are not used for all electrical circuits you may also find that you have to do the same thing with the various fuses.

Also note that GM style alternators can short out to ground as can any major piece of equipment on a boat. So also check to make sure both are charging. If one is not charging, it could be the cause, if it has shorted out.

Hope this information is helpful and easy to use.

Kevin Smith
Richmond VA
1991 250/270 Weekender, 7.4 Ltr, 330 HP, Bravo II