87 242 SR1: Low voltage readings
#1
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Joined: Jun 2014
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When both engines are running on hose in the driveway, my voltage meters are running about ten or even lower. Any thoughts on what could be going on? Just bought the boat and haven't had it in the water yet. Is this normal? Battery also seems to be going dead...and thoughts?
#2
I would check the output of the alternators. One could have been dead for a while, and the other will keep things going, but it isn't going to like all of the load and will eventually burn out. You may be in for a pair of new alternators.
#7
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Joined: Mar 2005
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From: Cape Cod, MA
Nothing normal about a 12v system running at 10 volts. You should have about 13.5 volts with the engines running.
So, like the others have stated, probably the alternators are bad. It would be unusual that both engines have bad alternators though . . . so maybe check the wiring first. How much do you know about the boat's history, test runs pre-purchase, etc?
So, like the others have stated, probably the alternators are bad. It would be unusual that both engines have bad alternators though . . . so maybe check the wiring first. How much do you know about the boat's history, test runs pre-purchase, etc?
#9
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Joined: May 2006
Posts: 281
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From: Covington, LA
I was going to suggest the same thing. If it's a one wire alternator they need enough RPM to "kick in" (so to speak). Definitely should be over 12V at idle and more like 13+ above 1500 RPM



